And, apparently, that’s why rat poison is so effective – who knew?!

I know there are other interesting facts about rats (like they really just like to have eat and have sex and they’ll have sex with any rat, male or female) but I did not know this one and I find it fascinating.

Scientists decided to find out why by studying their physiology and neurology.

LiveScience contributor Charles Choi explains:

They found rodents had bodily constraints that would limit how much they could vomit even if they could attempt it. This included reduced muscularity of the diaphragm, the thin sheet of muscle underneath the lungs, as well as a stomach that is not structured well for moving contents up the throat.

The researchers also investigated the brainstems of lab mice and rats. When given compounds that normally trigger nausea in other animals, the researchers saw less nerve, mouth, throat and shoulder activity normally linked with vomiting. This suggests they lack the brain circuits for throwing up.

It’s thought that they once could have but through time lost the ability to vomit in favor of other defenses.

Interestingly, horses can also not throw up. If a horse vomits, it’s considered to have a ruptured stomach and will die soon – so sad.