Beetles, flies, bees, butterflies and earwigs are all insects. Centipedes, millipedes, woodlice and spiders are not insects.
So, what makes an insect? Insect adults have six legs and three body sections (a head, a thorax and an abdomen). Most adult insects have wings too. Many insects can look very different when they are young though, for example a caterpillar that changes (or metamorphoses) into a butterfly adult that has all the characteristics above.
Counting the number of legs can be difficult whilst they are on the move for their next meal or finding somewhere to lay their eggs. One of the simplest things you can do to look closer at insects is make a “spy-pot”. Using a spy-pot can be a great way to temporarily keep a ladybird from flying or crawling away whilst you look closer. You can use it for lots of other invertebrates too, counting the legs on a centipede, for example.
To make a spy-pot, just get two clear plastic cups, cut off the bottoms and replace them with cling film or some clear plastic held on with a rubber band. Gently place or scoop the insect (or is it?) into one of the cups so it is sat on the cling film or plastic bottom. Then slowly put the second cup inside the first until the animal is held softly between the two cups.
You now have a perfect viewing apparatus for the invertebrate in question. Give it a go, a great way to look closer. Remember that insects can suffocate if they are left in the spy-pot for too long, so let go whatever you are looking at after two or three minutes.