Flea dirt is fecal material left by fleas. It consists of digested blood and looks like pepper on the pet's skin. When a pet owner places flea dirt on a wet paper towel, it spreads to create a small circle of blood, indicating the pet has fleas.
Effective flea control on pets involves understanding the pest's four-stage life cycle. Some products kill adult fleas while others prevent eggs from hatching. The female must have a warm-blooded host to lay eggs. Each female flea has the capability of laying hundreds of eggs during its life. Under ideal conditions, the egg hatches and the flea reaches maturity within 14 days. However, if conditions are less than ideal, the flea remains in the larva stage, protected by a cocoon, for an extended period. It emerges from the cocoon when it detects movement, heat and carbon dioxide, and almost immediately jumps on a host for a blood meal.
Prescription products in 2014 tend to offer better control of fleas than older products did. By preventing the hatching of eggs, these products break the life cycle of the flea. They offer control by treating the pet and eliminating the need to treat the entire home. However, they are less-effective for pets with continued exposure to fleas from other sources.