The answer to 'what causes flea' is that fleas are small, wingless insects that feed on the blood of animals, including pets and humans. Fleas typically enter the home through infested pets, outdoor areas, or on clothing and furniture. They lay eggs that hatch into larvae, which then develop into adult fleas, completing their life cycle.
Fleas thrive in warm, humid environments and can multiply quickly. They can cause itchy bites, skin irritation, and even transmit diseases to pets and people. Proper pest control and prevention measures are essential to eliminate and prevent flea infestations.