Rat Fact!
Rats cannot burp or vomit, the reason for this is that the barrier between their stomach and the esophagus is incredibly strong and their esophagus does not have the muscle strength required to push through that barrier, nor do they have the neural connections in their brain which are involved in causing one to vomit.
Although they do have an alternative, instead of eating a new food all at once, then feeling sick after, they have a taste and if they feel sick they wont eat that food again. (but most pet rats will generally trust their owner enough to eat any new food) something else (wild) rats do is eat dirt or clay to dilute the toxins in the rats body.
