Found these facts for you:
The eggs develop into larvae or caterpillars, which feed on organic debris around the home.The larvae pupate within a protective cocoon from which an adult flea emerges.
Growth & development from egg to adult normally lasts 3 weeks.
Flea facts:
most dogs & cats are affected by the cat flea, Ctenocephalides felis
flea ''dirt '' / faeces is seen as black flecks on the animals body that turn red when moistened
fleas eggs are laid in the house & garden; they are never found on the animal
flea larvae eat organic debris found on floor surfaces; they are never found on the animal
adult fleas can jump over 1 metre vertically
undisturbed, an adult flea may survive for over 3 months without feeding
female fleas begin laying eggs 2 days after their first blood meal
when one flea is seen, hundreds of offspring are likely to be present