Saxicolous Mouse

In Sir Walter Elliot's description it lives entirely in red gravelly soil, in a burrow of moderate depth usually on the side of a bank. When the animal is inside, the entrance is closed with small pebbles, a quantity of which is collected outside, and the pile of pebbles shows where its retreat is (Wikipedia, general species account).

The burrow leads to a chamber holding a bed of small pebbles on which the mouse sits, the thick, close hair of its belly protecting it from the cold and hardness of such a seat. Its food appears to be vegetable, and in its habits it is monogamous and nocturnal (Elliot, as reported on Wikipedia).