The eggs of fleas are small, whitish and barely visible to the unaided eye. The eggs are laid singly, usually among the hairs of a pet. The eggs are easily dislodged from pets’ hairs by slight vibrations and may drop on furniture, carpets or pets’ bedding. Usually 2 to 20 eggs are laid at a time. Under ideal condition, a total of 400 eggs may be laid over a period of 6-7 months. Within 2 days to 2 weeks, the eggs hatch into maggot-like, active larvae which are small, whitish and have brown heads. When fully grown, they are about 3 mm long.
They may be found in bedding of the host, or wherever the eggs might have been dropped or protection from bright light and will work their way into debris, into the deep pile zone of carpeting or other protective areas for coverage. They feed on organic matter and on the blood-containing faecal droppings of the adult flea. The larvae require moisture and thrive best in humid parts of the building, cracks and carpeting where moisture levels are higher.
When fully grown, the larvae a “cocoon” (in which they pupate) with particles of debris that are nearby. The pupal stage lasts 5 days to 5 weeks depending on conditions, or it may over winter. If a potential host steps on the pupal case when development is complete, an adult flea catapults out. The use of a vacuum cleaner may similarly cause the adults to emerge. The adult reacts to presence of carbon dioxide and warm temperature to locate its host.