Fleas are highly specialised bloodsucking parasites and have a formidable reputation of claiming more victims than all the wars ever fought as a result of the bubonic plague (Black death) in the 14th century where over 25 million people died.
Both male and female fleas rely on blood for their nutrition but can survive for several months without it. Most females will lay at least 100 eggs within a lifecycle of several months.
The main flea species that attack humans include the cat flea, dog flea and the human flea. The common cat flea is found on both cats and dogs and is the species usually identified in attacks on humans. The other two species are relatively rare.