Ticked Off

Predators are not the only creatures to feed off other animals. Certainly, if you're an antelope, the obvious things to fear are lions, crocodiles, or whatever else might seek to ambush and eat you. But virtually all animals, and certainly all mammals, also suffer from parasites, a rather more insidious threat.

Very broadly speaking, parasites employ one of two tactics. Endoparasites live in inside an animal, often in the gut if they're any larger than single-celled organisms, although they can infect other organs. These are typically parasitic "worms" of one kind or another, and fighting them off is more a matter of an animal's immune system than of any behavioural traits (at least, once it's already infected). Ectoparasites, on the other hand, live on the outside of an animal, clinging to the skin and perhaps hiding among the fur. Fleas are an obvious example of this sort of parasite and grooming can be at least a partial defence against them.

All the World's Deer: The Largest Deer and Other Oddities

Moose

It will probably come as no surprise that the largest species of deer alive today is the moose (Alces alces), confusingly known as the "elk" in some parts of Europe. The latter is, of course, the original English name for the animal, and remains, more or less, the name for it in languages such as German and Swedish today. The word "moose" comes from one or more of the Algonquian languages and entered English no later than the 17th century, although why Europeans chose to rename the animal they already knew about rather than come up with a new name for the novel American beast that looked like a red deer is unclear.

At any rate, moose are undeniably large, considerably larger than the American elk. They typically stand around 200 cm (6' 6") at the shoulder, with females not much shorter than males. The males are, however, significantly bulkier and more muscular, with a full-grown bull typically weighing between 300 and 600 kg (660 to 1300 lbs) and females around 25% less. The occasional exceptional individual can, of course, be much larger than this but, even ignoring those, that's pretty big for a deer.