How Big Are Cat Fleas?

When it comes to fleas, you can never be too safe. The size of a flea can vary greatly from one to five millimeters. Adult fleas are one to four millimeters long, while their legless larvae are up to five millimeters long. Adult fleas are brownish or white in color, and are a fraction of a millimeter in length.

Adult fleas complete their life cycle in as little as three weeks, but they can take longer if their environment is not ideal. Once a female flea lays an egg, it develops into a maggot-like creature within seven to fourteen days. These larvae feed on all organic matter, and they need a host to develop. Once they emerge, they feed off the host and pass within a week.

Female fleas lay four to eight eggs per blood meal. These eggs are about 1/64 inch long and will hatch after a period of one to 12 days. Female flea eggs are white or off-white in color. Larvae feed on dried blood and fecal material excreted by adult fleas.

Adult cat fleas lay their eggs on various hosts, including cats, mice, ruminants, and dogs. Female fleas lay eggs on humans and other animals, but they do not complete their life cycle on humans.