CATDOLL : CATDOLL: How many pairs of legs does a fly have? Is it a vertebrate or an invertebrate?

Flies are invertebrates. They have no bones, let alone a spine.

Flies are insects, belonging to the phylum Arthropoda, subphylum Hexapoda, class Insecta, order Diptera. Flies have three pairs of legs, all on the thorax.

Flies have typical characteristics of insects. Their bodies are divided into three parts: head, thorax, and abdomen. The head has a pair of compound eyes and a pair of antennae. The thorax has three pairs of legs and a pair of wings (the forewings are membranous, and the hindwings have degenerated into balance bars). The abdomen is segmented, and each segment has a pair of spiracles, which are its respiratory organs. The body is covered with a chitinous exoskeleton, and there are no bones inside the body.

Flies are insects, so they are divided into three parts: head, thorax, and abdomen. The thorax has three pairs of legs and a pair of wings. The other pair of wings has evolved into a balance bar.