Why are snakes and earthworms classified in different groups?

You would think that since the look a lot alike, they must be in the same classification. But that isn't so. There is too much that makes them different from each other.
Earthworms have no lungs, but they breathe through their skin and they need to keep it moist so that they can absorb oxygen from air. Earthworms produce both sperms and eggs, but they cannot reproduce on their own. They need other worm’s sperm to fertilize an egg. Earthworms can’t bear light because it paralyses them, so they always run away from it. Moreover, they don’t have eyes and lastly they are cold-blooded insects. But what is most important is that they don't have a backbone.

Snakes are coldblooded reptiles without limbs and they have a backbone which makes them a vertebrate (like humans are). They have eyes that don't blink. Other reptile species include tortoises, turtles, lizards, alligators and crocodiles