@ 649spar22 Ecto- or Exoparasites are external (leeches, fleas, ticks, tsetse flies, mites, mosquitos etc.) while endoparasites (e.g. parasitic worms) are, as their name suggests, internal. This is in part misleading for two reasons; the gut lumen is considered ‘outside’, although most worms have to travel through the body to get there, and many endoparasites have free living stages, e.g. Schistosomes, hookworms, Ascaris and many others. You’ll find that many things in Biology are never that clear-cut.
Nop! There are also parasites that live outside body…have you had head lice before? 😛 And if we extend the concept of parasites beyond things that affect human and animals, then we find other living things in the wild that live the life style of a parasites – that is to get their benefit at the cost of other living things.
There are birds (cuckoo birds) that lay their eggs in other bird’s nest and fool them to feed and raise up their young.
There are plants that poke their extension into other plants to take food and water, too!