Most of us learned how to tell arachnids and insects apart in elementary school, but classifying insects into their different orders based on looks alone is a little trickier. If you want to look at insects like an entomologist does, though, there’s one body part in particular you should focus on. According to a TED-Ed lesson by Anika Hazra, identifying the type of mouth an insect has can tell you a lot about what group it belongs to, what it eats, and how it evolved.

There are five main types of mouthparts insects can have, the most common of which is the chewing mouthpart. These mouths are characterized by large, serrated mandibles made for grinding up plants and prey. Believed to be the most primitive type of insect mouth still around today, you can see the chewing mouthpart on insects like ants and grasshoppers.

Other insect mouthparts include the pierce-sucking type, which is used by bedbugs and mosquitos to suck blood; the siphoning mouthpart, the curly, straw-like mouths that butterflies have; the sponging mouthpart, which helps flies sop up fluids; and the chewing-lapping mouthpart, which enables bees to build their hives as well as eat.

It’s important for scientists studying bugs to be able to recognize the diverse mouths of insects. It’s also a useful skill if you’re just a casual bug enthusiast. For illustrations of all the different mouthparts, check out the video from TED-Ed below.

[h/t TED-Ed]