Sources : Hemtra

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Quadrupeds 4.38): The hemtra, as the Liber rerum says, is a very small animal that lives in parts of Germany. The male and the female gather food in the summer, with which they live in the winter. They store these foods by making heaps on the ground. But by nature the female is greedy and prodigal in taking food. On the other hand, the male is parsimonious and avaricious beyond measure, so much so that he hardly wants to spend on himself even the meager living. But the male, knowing the greed of the female, blocks the door through which he can reach the hidden food. Now the female is naturally cunning and makes a secret opening for herself on the other side, through which she can steal the food, not knowing the sufficiency of her greed. It therefore happens from this that the male melts under the skin in the coming summer and on the contrary the female grows saturated with fat. - [Badke translation/paraphrase]