[eli5] Why do insects have lots of legs while larger animals have 4 or 2? Also, why aren’t there any animals (that I know of) with 3 legs?

Question

[eli5] Why do insects have lots of legs while larger animals have 4 or 2? Also, why aren’t there any animals (that I know of) with 3 legs?

In: 381

Answer 1

Starfish are radially symmetrical, and depending on the species can have a wide variety of legs, including 3. Most animals are bilaterally symmetrical, and so have even numbers to maintain balance and move efficiently.