"Fleas are wingless insects with mouthparts adapted for piercing skin and sucking blood. They are external parasites living off the blood of mammals(including bats and humans) and birds. Their legs are long, the hind pair well adapted for jumping: a flea can jump verically up to 7 inches and horizontally up to 13 inches. This is around 200 times their own body length, making the flea one of the best jumpers of all known animals (relitave to body size), second only to the froghopper. Adult fleas cannot survive or lay eggs without a blood meal, but may live for 1 year without feeding. The eggs take around 2 days to 2 weeks to hatch. " [1]

[1] Wikipedia