Finding carabids

This page is about some of the basic techniques for finding and catching carabids. The emphasis is on identifying and getting to know carabids in the field.

You will sometimes see carabids running about in the open, perhaps crossing a path or a patch of bare ground in the sunshine. However, the most reliable way of finding carabids is by looking under stones and logs. You will soon get a feel for the kinds of items that are worth rolling over – a huge, heavy stone or log is often no better than a smaller and lighter one! They mustn’t be too wet and mouldy underneath. Carabids like slightly damp resting places – not too wet and not too dry. Rubbish can be just as good as stones or logs!

Other good places to look are in tussocks – part the tussock and get right into the heart of it. Also look under rosettes of plants, and under mats of creeping vegetation.

Most carabids are largely nocturnal. Most coleopterists are largely diurnal. Going out beetling by torchlight can be very productive, and often gives the night shift of the local constabulary something to laugh about!

A good trowel is an invaluable piece of kit. It has to be said that many coleopterists don’t carry a trowel, but if you are targeting carabids, it is a great help for general rummaging around at the soil surface. Carrying a trowel can draw suspicious stares when visiting reserves with rare plants!

Fieldwork kit for carabids

Get your eyes to the ground. The closer you can get your nose to the subject, the more you will find. Kneeling, crawling around on hands and knees and lying down are all good ways of finding carabids. For this reason, looking for carabids on sun-baked dry heaths is more comfortable than in a wetland! A pair of knee-pads from a hardware store or garden centre is a worthwhile investment for added comfort: I swear by them. In wetlands, a pair of waders allows you to kneel down comfortably on muddy ground, in puddles and in shallow water-margins.

What to look for

Although many carabids are small and some of those are also quite brown and inconspicuous, they are all shiny, and most of them run about when disturbed. It won’t be long before you get a search image for shininess and movement. Of course it is not just carabids that are shiny and move, but it’s a start! Take time to stare after you’ve turned a rock over. Some species (e.g. Notiophilus) freeze awhile before sprinting off.

How to catch a carabid

Be firm! Most carabids are surprisingly tough, and you will do no real damage to them by firmly grabbing hold. Immature specimens, which often appear paler and more yellow than normal, do not have fully hardened exoskeletons, and they are easily squashed. Some of the flimsier species also require more delicate handling.

Even small carabids can be studied in the hand. This is Notiophilus aquaticus (c) John Walters.

Though mostly good-natured animals, carabids can bite! A few of the larger species have quite sharp and powerful jaws, capable of giving a nip, though not of breaking the skin. The effect of the bite is more of a surprise than actually painful. All species seem to regurgitate a small blob of unpleasant-smelling digestive juices upon anyone who irritates them. The rare bombardier beetle Brachinus crepitans has a more powerful armoury – it ejects an explosive chemical mixture from its posterior, earning it a place in the Guinness Book of Records! A few of the larger British carabids, including Cychrus caraboides and Carabus granulatus, are capable of squirting unpleasant chemicals (acetic acid?) – a few coleopterists have tales of getting an eyeful when examining such a beetle at very close range.

Once caught, it is possible to hold a carabid still by its legs and study it in the field under a hand lens. My big 8x lens gives a really good image in the field, backed up by the 15x to see smaller details.

If you’re going to keep a specimen, drop it into a tube. It sounds so easy, but many a good specimen has missed the tube and been lost in the grass! Keep tubed specimens somewhere where they will not get too hot, not receive direct sunlight (the greenhouse heating effect rapidly kills the beetles) and not get broken: a bum-bag works well, a trouser pocket doesn’t.

A pooter is a device for sucking insects into a tube. You cannot actually inhale the insect, because the mouthpiece is covered by a fine gauze. The big draw-back with a pooter is that it makes field identification very difficult. Still useful for sucking carabids out of crevices, or off very muddy surfaces, or when you just decide to catch absolutely everything that moves. Essential for when you move onto other beetle families.

Brian Eversham gets a carabid's-eye-view of a trowel

Many coleopterists carry a white tray (or any other colour) with them and it is a versatile and useful thing to have. Available in pet shops in a range of colours, I think sold as cat litter trays. Few carabids can climb out of one (though many can fly out on hot days) so it can be used to examine live beetles without too much risk of them escaping. Also useful for splashing (a technique for finding beetles at water margins) and for examining sievings.

Pitfall trapping

The basic concept of pitfall trapping is to dig a jar or cup into the ground, level the soil surface flush with the rim of the jar/cup, and leave it for unwitting animals to fall into. Glass jars, with sheer, slippery sides are very effective at preventing the animals from climbing out again. Plastic coffee cups and similar are more popular because they are lighter and less easy to break.

Pitfalls may be left for a few weeks if filled with an inch or two of a suitable preservative (dilute propylene glycol antifreeze (as sold in motor shops, etc.) is the best). You can run dry pitfalls to catch live specimens but they’d need to be somewhere where you can check them daily. Be aware that the catch may drown if it rains, and that if you catch a big predator, it may eat the others – drilling a small hole in the bottom and placing a few pebbles in the pitfall mitigates against both those problems. A rotten apple bait works well for many carabids.

Live pitfall trap. Rotten apple in the bottle attracts carabids, etc.


It is amazing how many animals do bumble into pitfall traps – chicken wire covers can help to keep out shrews and amphibians, and prevent dogs/foxes/badgers drinking the contents, but this is still a technique which kills a lot of animals and creates a lot of work identifying everything.

For detailed advice on pitfall trapping, download my Pitfall trapping protocol.

Beginner’s luck

Beginner’s luck is a genuine phenomenon. If you are a beginner, make the most of it! As time goes by, coleopterists settle into using the same old techniques and looking in the same types of places – perhaps not surprisingly, this often means finding the same old species. Beginners often do things that an experienced coleopterist wouldn’t bother with – and come up trumps! So, ignore advice and do your own thing!


12 Comments

  1. Mike Edwards says:

    Mark,
    The sieved catch from the pitfall trap is sorted & transferred to 70% alcohol. Can the individual insects be set directly from this, or do they need to be treated with some other solvent (eg water, fresh alcohol) or some other process (eg cleaning & then relaxing with dilute acetic acid) before they are carded?

  2. markgtelfer says:

    Mike, You can take beetles straight from 70% alcohol, dry them on some tissue and card them. However, the dehydrating effect of 70% alcohol means they will probably be quite stiff and difficult to card neatly. If you’re only storing specimens for a few months, 50% or 60% alcohol is better. Better still, store your pitfall catches in dilute acetic acid.

  3. Yikai Zhang says:

    I have never tried pitfall trapping without a bait before, does it work well? What I find very frustrating is that most of my pitfall traps, because they have a strong odour, get dug up by dogs! I am very interested in carabid beetles, especially Carabus and Leistus. Does anybody have any good advice on how to collect them?

  4. markgtelfer says:

    Unbaited pitfalls certainly do catch a lot of beetles. Must be worth a try if your baited pitfalls are getting dug up.
    To find Carabus and Leistus by day, I would concentrate on turning over logs and stones. But both genera are easier to find by looking for active beetles at night with a strong torch.

  5. Yikai Zhang says:

    I live in the heart of London, and since I’m a student, sometimes it’s difficult to find good collecting sites without using much time.
    Can anybody recommend any good spots in or around London that is good for carabids?
    Although I must admit carabids now seem to be rather scarce in London. There are large numbers of Pterostichus madidus, P. niger, Abax parallelepipedus and Platynus assimilis, however apparently ‘common’ species such as Carabus violaceus, Carabus nemoralis or Cychrus caraboides seem to be very scarce in the Greater London area, despite plenty of suitable-looking habitats. Can anybody explain why?

  6. markgtelfer says:

    Carabus and Cychrus are large beetles that walk large distances when foraging and get killed by trampling, being run over by vehicles and by falling into drains and other accidental pitfall traps. As flightless species, it is difficult for them to recolonise areas once they’ve gone locally extinct.

  7. Mel O says:

    I’m just getting started in carabid collecting and am planning to set pitfall traps with preservative rather than collecting live but have had conflicting advice as to whether propylene glycol is still not great for mammals (although definitely nothing like as bad as ethylene glycol). Have you had any problems with propylene glycol? I read that saline solution can be used instead – have you ever tried this as I imagine that it could stiffen/damage some specimens? Any advice gratefully received.

  8. markgtelfer says:

    Mel O, I thought propylene glycol was a harmless substance used as a food additive? I’ve never used saline solution but there’s been some good discussions about the pros and cons of this and other pitfall trapping liquids on the beetles-britishisles yahoo group. I recommend you join (if you’re not already a member) and search the message archives. Mark

  9. Mel O says:

    Thanks so much for the advice. I hadn’t found the yahoo group but will join now.

  10. Stuart Campbell says:

    Hi Mark, Just wondered whether or not your Vitrex knee pads are “model number” 302452 ? Would you recommend these over over makes and other Vitrex models ?
    Many thanks.

  11. markgtelfer says:

    Hi Stuart, Yes the Vitrex 302452 looks like the ones I have and they don’t look like they’re going to wear out in a hurry (I’d worn out a couple of pairs of Vitrex 302459 before I got these).
    Sore knees full of thorns and brambles are a thing of the past, and they’ve spared me from a few broken glass injuries, kneeling on dogshit, etc. Well worth it!

  12. Stuart Campbell says:

    Hi Mark, Thanks for the info – appreciated !
    Cheers.

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