Somewhere in the vastness of Tanzania or Uganda, a member of a pygmy tribe went hunting to feed his family. To kill the animal, he relies not on the power of his small bow, but on a strong poison with which he lubricates the arrowheads. The hunter made poison from the sap of the Abyssinian acokanthera plant (Acokanthera schimperi), but what is surprising is that an African crested rat lives next door to him, which also uses this plant for similar purposes. Only the rat wants not to kill, but to defend itself.
Since their discovery in 1867, crested rats have been considered poisonous. Researchers and hunters have repeatedly observed how hyenas, young lions and dogs died of poisoning after grabbing rats with their mouths. It quickly became clear that the poison is located on certain hairs in the rat's fur, as it were, covered with poisonous fur armor. But the origin of this poison was unknown, and no one was interested - it was believed that the rat's body produces it naturally.
The change came in 2011, when someone noticed that a rat was chewing on the bark of an acocantera while licking stripes on its fur at the same time. Scientists from Kenya captured 25 rats and recorded more than 1000 hours of video observations of them, as a result of which they found out that the rodents are deliberately engaged in obtaining poisonous saliva. An autopsy showed that these animals have an unusual four-chambered stomach with such a powerful microflora that toxins dissolve in it without any harm. And the poisonous saliva obtained from chewing is used by rats as a protective coating against large predators.
The poison used by crested rats is cardenolide compounds, which are deadly for all mammals, even in micro doses. There is a bizarre evolutionary "life hack", rats have learned to create and use a poison that ideally kills predators, since it immediately gets on the mucous membrane in the mouth when it comes into contact with the rodent's fur. Bite or grabbed - immediately poisoned - quickly died. For small rats 25-36 cm long, with funny faces, without claws and fangs, this is an excellent and unexpected remedy. But how did rats learn to extract poison from plants and use it so effectively?
Tufted Rat Hair