The cat flea measures up to 3 mm and is brown/black in colour. Cat fleas are tiny parasites that feed on the blood of animals. Heavy infestations in structures can be very stressful especially when humans are being bit. Severe skin reactions can lead to hair loss and open wounds in people and pets. The female flea can lay 20 or more eggs per day. They may be found in bedding, carpeting, under baseboards and deep into the floor voids. 400 eggs may be laid over a 6-7-month period. Fleas thrive in warm, humid environments, which means late summer is the peak season for fleas.