Dec 27, 2016 · But not even all hind gut fermenters are the same. Some, mostly larger species, like horses (and rhino), ferment primarily in the colon. Others—mostly cute little critters like bunnies (or rodents, which, admittedly, are polarizing when it comes to opinions about cuteness)—ferment mostly in the cecum, a dead end sac that is like our appendix, only lots bigger.