Pitfall trap

Catching creepy crawlies

Build a pit-fall trap and discover what's crawling around your garden at night

Pit-fall traps are simple to make. Our scientists use them to collect specimens for their research and to add to the Museum’s collections. What will you find in yours?

Pitfall trap in the garden

A finished pitfall trap, ready for bugs to fall in

You will need:

  • a trowel
  • a plastic cup
  • 4 small stones
  • a small piece of wood or a wide flat stone

How to make a pit-fall trap

  1. Choose where to put your trap. Rainwater will ruin your trap, so don’t place it at the bottom of a slope where water could run in.
  2. Dig a small hole in a bare patch of ground, and put your plastic cup in it.
  3. Fill in any empty space around the outside of the cup with soil. Make sure that the top of the cup is level with the ground - if the cup sticks up you won't catch anything.
  4. Make a ‘roof’ to stop the rain getting in. Balance a small piece of wood or stone on 4 small stones (one in each corner). Leave room for bugs to slip in.

Can you catch a centipede? They have at least 30 legs.

How does it work?

Any bugs that walk where your trap is will not realise the cup is there and may fall in.

What to do next:

Check your trap the next day. Don’t leave it any longer, or you might harm any creatures you catch. Pull your cup out of the ground and have a look at what’s inside.

Write down what you see. Draw or take photographs of the creepy crawlies you catch.

You can use an identification guide like the OPAL Bugs Count Pocket ID Guide to identify what you’ve found.

Pill woodlice

Will you trap a woodlouse? Pill woodlice curl up when disturbed.

Make sure you release everything back into the wild. You can re-set your trap and check again the next day to see who’s wandered past.

What are you likely to find?

Invertebrates like beetles, millipedes, centipedes, woodlice, ants, spiders and worms.

This article was originally published in Wild World, our magazine for kids.