What you Need
A plastic cup
A small trowel (something to make a small hole)
Somewhere to put the hole - eg a garden.
Half a bucket / Ice cream container (optional)
What to do
All you need are some plastic cups and you need to find a patch in your garden where you can safely dig. Don't dig up the middle of your lawn or anything like that. Just dig a small hole in a flowerbed or under a bush.
Put the cup in and make sure the surface of it is completely flat with the soil, so that any insects walking along can easily walk into it. What you could also do is put half a bucket over the top of it to protect it from the rain and the sun.
Then leave the trap for a few hours, maybe overnight, come back and see what little monsters you have caught.
What may happen
Sam found a springtail - They've got six legs but they're not actually insects. They're called non-insect hexapods. They look as though they're about 3 or 4 millimetres long. They crawling around like ants but with longer antennae. They have a spring at the end of their tails, which is a little structure that looks a bit like an arm. They can straighten it very fast and will propel them into the air, so it's an escape response. The reason is that these things are eaten by nearly everything, so that's why they're a bit nervous and twitchy animals. Everything's trying to munch them.
Luke Caught a pill woodlouse. Its response is to curl up a little bit like an armadillo and protect itself from predators.
Why does it happen?
You may find that traps in dark shady places work a lot better than in the sun, as insects feel a lot safer from big predators like birds.
If you want to identify the bugs you find you could try:
Part of the show Social Insects and Locust-Inspired Car Safety from the 18th Jun 2006