Rat (species)

Rats (Rattus rattus) are a species of mammal native to Earth.

They appear on most of the campaign levels set on Earth, as well as the multiplayer map Rat's Nest in Halo 3. It is possible to kill them. When they are shot at or encountered they will squeal characteristically and will appear as small red dots on your motion tracker. when killed they will roll around in a prone form. Rats have been noticed around the butchered area of the barracks, most likely feeding on the deceased marines.

It is noticeable after five hundred years that the rats have not changed physically through natural process they should have evolved at least multi-chromatic fur(dark in summer, light in winter) and gotten slightly bigger.

It is unknown how the covenant react to rats as they are true vermin.

It is also speculated that they may be used as a small food source (albiet an unpleasent disease riddled one) by Grunts, Brutes and Jackals.