Juan Manuel Borrero / Illustration of Pinworms / Threadworms (Enterobius vermicularis) and eggs. Pencil and watercolor painting.

Juan Manuel Borrero / Illustration of nematode (Rhabditis sp) anatomy. Pencil and watercolor painting.

Philippe Clement / Horse / Equine roundworms (Parascaris equorum) in horse dung, France

Philippe Clement / Horse / Equine roundworms (Parascaris equorum) in horse dung, France

Dave Bevan / Nematode worm {Nematoda} which helps to break down vegetable matter into compost, Wales, UK, May

Tony Phelps / Roundworm found insde African Rock python {Python natalensis} South Africa.

Tony Phelps / Roundworm infestation of captive African Rock python {Python natalensis} South Africa.

Kim Taylor / Round worms {Toxocara canis} from the gut of a domestic dog, UK.

Kim Taylor / Round worms {Toxocara canis} from the gut of a domestic dog, UK.

Kim Taylor / Free living marine Nematode {Nematoda}