Frequently Asked Questions

There are several questions about Dragonflies and Damselflies that are often asked. This page attempts to answer some of those questions. We can't promise that you will find the answer to the question that is of most interest to you here but if you have a question that you think we may be able to answer please send us your question and we will do our best.

What is the difference between Dragonflies and Damselflies?

Dragonflies and damselflies belong to the insect order known as Odonata, meaning "toothed jaw" - their mouthparts are serrated. They are often referred to collectively as "dragonflies", however there are two different sub-orders.

Damselflies are insect in the sub-order Zygoptera (meaning "yoke-winged"). All four wings are near enough equal in size and shape. They are usually small, weakly flying insects that stay close to the water margins or water surface. When at rest, most species hold their wings along the length of their abdomen. The eyes are always separated, never touching. The larvae have external plates (lamellae) at the end of the abdomen, which act as accessory gills.

Dragonflies are insects in the sub-order Anisoptera (meaning"unequal-winged"). Hind wings are usually shorter and broader than Fore wings. They are usually larger, strongly flying insects that can often be found flying well away from water. When at rest, they hold their wings out from the body, often at right angles to it. The eyes are very large and usually touch, at least at a point. The larvae have no external lamellae.

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Do Dragonflies Bite or Sting?

No, although large dragonflies if held in the hand will sometimes try to bite, but fail to break the skin. They have a lot of "folk names" which imply that they do (such as Horse stinger), but they don't use their egg-laying tube (ovipositor) for stinging. They also don't bite (people) but they are a fearsome predator of other flying insects.

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Why are they called Dragonflies?

Possibly the earliest reference to the name is from Francis Bacon's "Sylva Sylvarum: or a Naturall Historie in Ten Centuries." (a curious hotch-potch of experiments, observations, speculations, ancient teachings, and analytical discussions on topics ranging from the causes of hiccups to explanations for the shortage of rain in Egypt). It was artificially divided into ten chapters, each consisting of one hundred items and was published in 1626, where he first used common name "Dragon-fly". At a guess, Bacon had picked up on a common, folklore name in use at the time. Prior to this date (and since) many different vernacular names have been used. Some are: Adder Bolt, Snake Doctor, Devil's Riding Horse, Horse Stinger and Devil's Darning Needle.

There is an excellent paperback called "Spinning Jenny and Devil's Darning Needle" by M. Jill Lucas which has a great deal about dragonfly folklore.

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How long do Dragonflies live? Is it true that they only live for one day?

At the shortest, a dragonfly's life-cycle from egg to death of adult is about 6 months. Some of the larger dragonflies take 6 or 7 years! Most of this time is spent in the larval form, beneath the water surface, catching other invertebrates. The small damselflies live for a couple of weeks as free-flying adults. The larger dragonflies can live for 4 months in their flying stage. In Britain, lucky Damsels seldom go more than two weeks and Dragons more than two months. Most Damsels rarely go more than a week, and Dragons two or three weeks. They die from accidents and predation, and large numbers from starvation - in poor weather neither they nor their prey can fly.
No insect has a lifespan of only one day - even mayflies (not closely related to dragonflies) live for several months underwater as larvae before emerging as winged adults. Adult mayflies may only live for a day or so as they are dedicated "breeding machines". They cannot feed as adults as (most) don't have any functional mouthparts.

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What's the biggest/smallest dragonfly?

In the UK dragonflies reach a length of about 85 mm and a wingspan of about 120 mm. This is the size for the larger "Hawker" dragonflies such as the Emperor and Brown Hawker. Damselflies, which are the much smaller and weaker flying relatives of dragonflies, are much smaller. The largest in the UK are the Demoiselles. These have a body length of about 50 mm and a wingspan of about 60 mm.

The biggest wingspan of a living dragonfly is the Central American Megaloprepus coerulatus with a wingspan about 19 cm. This is a thin, long-abdomened damselfly. The bulkiest dragonfly may be Petalura ingentissima from Australia (female wingspan to about 16 cm), a central African Anax species or a reported, but apparently uncollected, aeshnid from Borneo. Perhaps the smallest Dragonfly is Nannophya pygmaea from east Asia including Malaysia and Japan. This species is only 15 mm long with a wing span of about 20 mm.
In prehistoric times dragonflies were much larger, the largest flying insects ever. The largest member of the extinct Protodonata was the Permian Meganeuropsis permiana with a reconstructed wingspan (based on fragments, scaled to complete fossils of similar animals) of about 70-75 cm.

All the links in this answer take you to photos, displayed in a new browser window, outside the BDS web site.

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How fast do they fly?

The maximum speed of large species like the hawkers is around 10-15 metres/sec, or roughly 25-30 mph. Average cruising speed is probably about 10 mph. Small species, and especially damselflies, are generally slower, although many medium-sized species can probably keep up with the largest ones.

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How quickly do Dragonflies get their adult colour?

When dragonflies and damselflies first emerge from their water-borne larval stage, most have very muted colours. Depending on weather conditions, it can take a few days for them to gain their bright adult colour. Common Blue damselflies are often a pale pinkish-brown rather than sky-blue on first emergence. Some damselflies, Blue-tailed are a good example and undergo a gradual colour change as they age. The females have several different colour forms, some change from violet to rich brown, others from salmon-pink to blue. Some of the larger dragonflies also change colour as they age. Some old females may start to develop the colouration of the males. Examples are Common Darter, which goes from yellow-brown to reddish brown, and Black-tailed Skimmer, which goes from yellow-brown to a blueish-grey.

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What is the lifecycle of the Dragonfly?

Greatly simplified, the life cycle is Egg (usually laid under water), Larva (free moving, water dwelling nymph) and Adult.
The larva lives for several weeks (or years depending on species) underwater and undergoes a series of moults as it grows. It emerges from the water when it is ready to undergo its final moult where the "skin" splits to release the winged adult; much as a Butterfly or Moth emerges from its pupa.

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What do Dragonflies eat?

Mainly, adult dragonflies eat other flying insects, particularly midges and mosquitoes. They also will take butterflies, moths and smaller dragonflies. There is one Asian species which takes spiders from their webs!
The larvae, which live in water, eat almost anything living that is smaller than themselves. The larger dragonfly larvae are known to catch and eat small fish or fry. Usually they eat bloodworms or other aquatic insect larvae.

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Can I use Dragonflies to control mosquitos or other flying pests?

Dragonflies certainly do eat large numbers of flying pest species, but using them to control these pests is not really feasible. There have been a number of studies carried out and only in very restricted and tightly controlled environments have Dragonflies, or their larvae, been shown to be able to control pest numbers. In the open, there is no reason to suppose that Dragonflies introduced to a pest rich habitat will stay there. Indeed, they certainly will not if other aspects of the environment do not suit them. It follows from this that your best chance of getting Dragonflies to prey on pests is to develop the habitat so that it is particularly suitable for Dragonflies, a worthwhile aim in itself! See the BDS publications "Dig a Pond for Dragonflies" and "Managing Habitats for Dragonflies" for more details of how to do this.

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What enemies do Dragonflies have?

Dragonflies do have enemies. Among the species that catch and eat adult dragonflies and damselflies are birds (e.g. Wagtails and Hobbies), Spiders (many damselflies are caught in webs), Frogs, and larger species of dragonflies (which catch and eat other dragonflies and damselflies). In the larval stage, which is spent underwater, they are preyed on by fish, frogs, toads and newts, other water invertebrates - and Kingfishers (see photo below).

Their defences include their excellent eyesight and flying skills which can help them to evade capture. Some are coloured black and yellow, or black and red, which is the universal warning colouration and may deter some of the bird predators.

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Are there any legends and myths about Dragonflies?

There are many legends and myths about dragonflies and damselflies from all parts of the world. Many are evident from their common nicknames. In the UK, Dragonflies were called 'Horse-Stingers'. This name may come from the way a captured dragonfly curls its abdomen as if in an attempt to sting. Another possible explanation of this name is that the big Aeshnids etc. are/were often seen flying round horses in fields. Here they were actually feeding on the flies attracted to the horses. Occasionally a fly would irritate/bite a horse enough to make it twitch or skip about. People seeing it made the inference that it was the dragon, being big and obvious, stinging, rather than an unseen fly biting.
An old name for damselflies was 'Devil's Darning Needles'. This stems from an old myth that if you went to sleep by a stream on a summer's day, damselflies would use their long, thin bodies to sew your eyelids shut! Naturally there is no truth in either myth
Similar myths are found throughout the world. You can find more about them by visiting Cultural Odonatology References, a site which has reference material relating to myths, legends, folklore and cultural significance of Odonata throughout the world. For more myths, and mythical names used in Europe you could visit Swedish Dragonflies where you will find a page of such items. (Both these links will open in a new window.)

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Do Dragonflies have antennae (feelers)?

Yes, Dragonflies do have a pair of antennae. They are very tiny and difficult to see. If you look at the photo on the right you will just be able to see the antennae between the front of the eye and the front of the face of this Emperor dragonfly. As dragonflies rely much more on their eyesight than on a sense of touch or smell, they do not need the large antennae found on some beetles and moths.

Head of Emperor Dragonfly showing huge compound eyes and small antennae

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Why do Dragonflies sometimes appear in large swarms?

Several species of dragonfly are known to collect in large aggregations or swarms. In Europe, the Migrant Hawker (Aeshna mixta) and the Four-spotted Chaser (Libellula quadrimaculata) have been observed to do this.  In most cases this appears to be due to very favourable feeding conditions in the locality. It may also be a "courting" group with males actively searching for females. This is less likely as males are much more aggressive to each other when looking for a mate.
The Four-spotted Chaser occasionally collects in these large aggregations before making a mass movement to another locality (like a bird migration). The reasons for this are unclear but may be due to population pressures.  There are records from the US of migratory assemblages of species such as the Green Darner (Anax junius) and various species of Saddlebags (Tramea).

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I have seen a dragonfly repeatedly dipping its ‘tail’ into the water – what is it doing?

It is laying eggs.  While damselflies and some dragonflies will settle on vegetation and insert eggs into stalks and other material in or near the water, many dragonflies will fly across the water dipping the end of their abdomens into the water and releasing eggs. These eggs are surrounded by a jelly-like substance which enables the eggs to stick to vegetation or the bottom of the pond.  Some species will remain paired while the female does this, while in others the male will fly nearby to guard the female from the attentions of other males.

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How good are dragonflies’ eyes?

Dragonflies have extremely good vision, which they use to locate and catch small insects in flight.  Like most insects, they have compound eyes. In the case of dragonflies the eyes contain several thousand individual facets, each containing a tiny lens.  Each individual lens has a low resolution but by combining the images from all of them dragonflies can achieve a level of resolution that is better than most other insects and thus their sight is particularly good.  They use their amazing sight to catch other insects in flight, in addition to spotting potential mates and predators. Visual acuity varies between species, with migratory dragonflies having the best sight and damselflies with their rather smaller eyes somewhat less, but still very good.

I have a dragonfly stuck in my conservatory / garage, what can I do to help it?

Open the doors and windows and leave it to find its own way out if possible.  If it does not find its own way out after leaving the doors and windows open for some time, you could try gently ushering it out with a newspaper.. As a last resort, grasp the base of the wings firmly between your fingers and release it outside quickly.

There is a dragonfly that has been resting on my wall / hedge for a day, is it ill – what can I do to help it?

The best advice is to leave it.  If it is recently emerged it will just be resting to gain strength to start its adult life.  If it is cool it may be just gathering any sun or other warmth to enable it to fly (temperature has a significant effect on dragonfly activity levels).  It may have just found prey and is digesting its meal with no need to eat again for a little while.  It uses a lot of energy to fly so it will only do so it if there is a purpose – usually to find food or a mate.  Even if it is unwell there is not really anything that can be done and it is best left alone. If deemed necessary, move it to a safe location, such as high up on some sheltered plants in a sunny location, by grasping it firmly by the base of its wings.

I have found a dragonfly that has a damaged wing – will it still be able to fly – what can I do to help it?

Dragonflies can usually fly with a damaged or even missing wing, unless it has been damaged during emergence from its larval skin. If so, it is likely to be perched near to water. Emerging or newly emerged dragonflies are very vulnerable to damage by rain or strong wind, or attack by other creatures (e.g. birds or cats) until their wings harden. A mature individual with a ragged wing will be a less accomplished flier, but may still catch prey and survive quite well.  Hard as it may seem, if it has a damaged wing and can’t fly, there is nothing that can be done to help it and the best advice is  to leave it alone. 

Where is a good place to see dragonflies?

Dragonflies associate with water so the best place to start is a local pond, lake or river that is reasonably unpolluted.  If you have a nature reserve locally that has a water body then that is likely to be a good place to visit.  Different species are associated with different types of habitat.  You can check our ‘Dragonfly Habitats’ page to see what you are likely to see at ponds / rivers / streams etc.  Dragonfly sightings are listed on our “Latest Sightings” page; somewhere near you may be mentioned.  We also lists of good dragonfly sites throughout the UK on our website at www.british-dragonflies.org.uk/content/where-see-dragonflies, as well as details of sites Wales and Scotland in the Welsh and Scottish project pages of our website.

Consider coming along to one of the many BDS field meetings held each summer. Check our events page, which lists dragonfly events held by us and other organisations, to see if there is anything happening near you. Even if you can’t go on the walk it may provide a good idea of sites that are worth visiting.

How do I create a pond for dragonflies?

We have produced a great booklet called “Dig a Pond for Dragonflies”, it tells you all of the things that you need to consider when creating a pond and has a list of plants that are good for wildlife ponds. Click here to download it.

I have a pond but cannot seem to get dragonflies and damselflies to live in it – is there anything I can do to encourage them to use it?

Have a look at our “Dig a Pond for Dragonflies” leaflet. This will provide some guidance on the key features that will attract dragonflies to your pond.  Generally the pond needs to be a reasonable size, 2m2 at least, containing varying depths of water with at least one portion where the side slopes into the water and contain a mix of vegetation both in and around the water, without being too overgrown.  Always try to choose native plants of local provenance and avoid non-native invasive species.

We also have a leaflet on ‘Managing Habitats for Dragonflies’; there may be some useful tips in this.

I have created a small pond and want wildlife to use it, I have put fish in it. What can I do to get dragonflies and other wildlife to use it?

The simple answer is “with great difficulty.”  The fish will eat the dragonfly larvae and while fish and dragonflies may co-exist in lakes and large ponds, they will not do so in a typical fish pond in a garden.  The fish will typically exist at a density that does not allow dragonfly larvae and other aquatic insects to flourish or even survive.  You will have to choose whether you want a pond for fish or for other wildlife – or even better, dig a second pond for wildlife!

I have bought some pond plants for my aquarium and a dragonfly / damselfly has emerged and is flying around my house – what shall I do?

This seems to be occurring more frequently. The species concerned are often exotic species that have been imported as eggs or small larvae on or in plants from other countries.  It is illegal in this country to deliberately release non-native species into the wild without a licence.  This is because too many introductions of non-native species in the past have led to unforeseen and unwanted consequences for our native wildlife or our economy.  It is unfortunate, but unless you are certain that the insect is a native species you should not allow it to escape into the wild.  Hard as it may seem, the best approach is to kill any insect in these circumstances.  The most humane way is probably to put it into a container and then into a freezer.

I have a dragonfly / damselfly emerging in my pond and it has started raining, the rain looks like it may damage the dragonfly – should I do anything to help it?

Rain is a natural hazard in our climate and dragonflies are surprisingly robust and able to withstand it.  Certainly they are less at risk from rain than from a human trying to move them while their body and wings are still soft.  If it is possible to shield the emerging dragonfly in some way without touching it, this may be worth doing, but don’t cover the dragonfly as it will need to fly as soon as it has fully emerged and its wings hardened a little, provided the sun comes out.  It will then find its own shelter.

A larva on a stem in my pond has stayed in place for some time.  Is it alright?

Check that it is a larva and not an exuvia. The exuvia is the larval case that is left behind after a dragonfly or damselfly has emerged.  Look a little closer if you can without falling into the pond.  If the dragonfly has emerged, you may be able to see a split on the head and thorax, where the dragonfly squeezed out, and some thin whitish tendrils around the hole.  Only very occasionally will a larva emerge from the water and die before the dragonfly emerges.  There is no practical help that can be given in such cases and any attempt to intervene when problems are suspected is likely to damage an insect that may just be slow to emerge.