Pitfall traps

A small pitfall trap is a simple method for catching ground-dwelling creatures such as beetles and woodlice.

Pitfall Traps

A small pitfall trap is a simple method for catching ground-dwelling creatures such as beetles and woodlice. These traps are a great way of seeing what small creatures live in your local surroundings, and it doesn’t harm the creatures in any way - as long as you check it regularly, are careful with creatures and put them back afterwards.

Things you might need:

  • Soft ground
  • Lidded tin can or similar
  • Some small rocks
  • Board or slate

Activity details:

Age: All
Difficulty: Easy
Preparation time: 30 minutes
Running time: Days

Learning points:

  • What species live outside your home
  • How to survey biodiversity responsibly
  • How to make an effective trap

How to make a pitfall trap:

  1. Dig a hole the size of the can, making sure your can fits neatly into the hole, with its rim level with the ground.
  2. Once the can is in place, position four rocks around it and balance a board or slate on top. This will provide a dark space, protected from rain and debris, which will attract ground-dwelling creatures.
  3. If heavy rain is forecast, or you will be unable to attend to your pitfall trap, you should put the lid on the can so that creatures don’t get caught inside and drown.

If you’ve found a bug but need help identifying it, take a look at our page on Identifying Nature for some advice.

Creatures you might find in your pitfall trap
Name Scientific class How to identify Interesting fact
Ants Insecta Small slim body with bed head and bottom Ants form societies and can communicate by producing subtle smells
Beetles Insecta Oval bodies with hardened front wing-cases Beetles are the most varied of all Insects, with over 350 thousand different types
Centipede Chilopoda Long segmented body - each section has one pair of legs No centipede has exactly 100 legs as they always have an odd number of pairs of feet
Millipede Diplopoda Each body segment has two pairs of legs Unlike centipedes, millipedes are mostly vegetarian
Spiders Arachnida An 8 legged creature with 6-8 eyes Spiders have special muscled jaws which are called chelicerae
Woodlice Malacostraca Oval shaped with 14 legs and a tough exoskeleton There are around 35 different species of woodlice in the UK
Pitfall trap
An illustration of what a pitfall trap might look like

Take care!
Make sure you check the pitfall trap at least once a day, removing any creatures you find there.
Remember to take care with your creatures and place them back in their usual habitat.
Finally, fill in any holes after you’ve used them.

How to take your investigation further...

Every species is different and they prefer different things. For example, some creatures will prefer living in damp, wet places, but others may prefer a drier, warmer environment.

Investigate what creatures fall into your trap on different days and during different seasons. A good way of seeing trends is to keep tallies of all the creatures you see so you can compare them.

Does the type of creature you attract change when you add small bits of food as bait?