Fleas are a parasite, with adults feeding on the blood drawn from a host, while larvae feed on organic debris, mainly the faeces of adult fleas, which contain undigested blood. Fleas commonly prefer to feed on hairy animals such as dogs, cats, rabbits, possums, rats, mice and other domesticated or wild animals.
It is important to understand that when feeding a flea is able to transmit disease-causing organisms. With several human diseases being spread by fleas, including the bubonic plague and murine typhus. The fleas most likely to deliver these diseases to humans are the rat fleas (Xenopsylla cheopis), which are found all over the world. The cat flea and the dog flea also bite people, but these species generally are only irritating rather than dangerous. The human flea (Pulex irritans) even implies this in its Latin name as fleas bite often lead to allergic reactions. More serious is the role of dog fleas in the life cycle of tapeworms that may infect children.
Another flea behaviour we are commonly asked about is “Can flea’s Fly”