A female lays several hundred eggs in a lifetime. Over a two week period they can complete a generation. Flea eggs are laid and mature in places where your pet frequents often a favorite chair, bed, carpeting. They spread disease by feeding on infected animals and then in turn transmit desease to man. Pest control operators will not treat animals.
Fleas are basically an animal problem.
But when fleas become a people problem, start by giving your home a thorough cleaning to clear eggs from baseboards, rugs, upholstery, floor and wall cracks, ventillators, closets, etc. The female Black Widow is usually black except for a red hourglass marking on her stomach. The Brown recluse is brown with a violin-shaped marking. Seek immediate medical attention if a bite is suspected. Do not ignore any spider bite.