How to Make a Pitfall Trap

A pitfall trap is an essential tool for catching and studying ground-dwelling insects, particularly springtails and ground beetles. It's easy. You can build and set up a simple pitfall trap in about 15 to 20 minutes using recycled materials.

What You Need

• coffee can with a plastic lid
• four rocks or objects of equal size
• a board or piece of slate wider than the coffee can
• a trowel

Instructions

1. Assemble your materials.
2. Dig a hole the size of the coffee can. The depth of the hole should be the height of the coffee can, and the can should fit snugly without gaps around the outside.
3. Place the coffee can in the hole so the top is flush with the surface of the soil. If it doesn’t fit correctly, you will need to remove or add soil to the hole until it does.
4. Put the four rocks or other objects on the soil surface an inch or two from the edge of the coffee can. The rocks should be spaced apart from each other to make “legs” for the board that will cover the pitfall trap.
5. Put the board or piece of slate on top of the rocks to protect the trap from rain and debris. It will also create a cool, shady area that will attract ground insects seeking moisture and shade.

Tips

• Close the coffee can with the plastic lid when you cannot attend to your pitfall trap, or if heavy rain is expected.
• Make sure to check the trap at least once every 24 hours, and remove any insects you have caught. Keep them for study or release them.
• If you want specimens for a collection and don’t need the insects to be alive, pour one inch of water in the pitfall trap and add 1 or 2 drops of dish soap.