Fleas: A Worldwide Pest When we think of fleas, we usually think of pets. Cats and dogs can regularly be seen scratching because of these tiny parasites, and preventing or checking for them is a regular part of pet care. But fleas can bother livestock animals too. With over 2,500 species, fleas are diverse and worldwide pests. On top of that, they can carry a host of diseases. Historically, rat fleas were responsible for the spread of bubonic plague across…