A number of diseases are transmitted by fleas, including epidemic typhus and bubonic plague Fleas also carrytapewormsfrom dogs and rodents and occasionally transmit them to humansFleas are.generally less than three-sixteenth of an inch long.More than 2,400 fleaspecies exist worldwideThe lifespan of fleas on dogs is usually more than 100 days, in which time a pair of fleas and their descendants can produce millions of offspring A female flea.consumes 15 times its body weight in blood daily Fleas are attracted to animals by body heat, movement,and the carbon dioxide they exhaleF.leas accelerate the equivalent of 50 times faster than a space shuttle does after liftoff. Fleas can jump up to 50times the length of their bodies wieghtup equivalent to a person jumping nearly a thousand feet.