The yellow-necked mouse is active all year round and does not hibernate. Sometimes several mice will huddle together during the winter to preserve heat. It is an excellent climber and scrambles around in trees and bushes. It lives in crevices, burrows at the base of trees, holes in tree trunks, hollow logs and bird nesting boxes and sometimes enters buildings. The burrows are often extensive with many entrances and complex layouts. It makes extensive stores of food such as acorns and beechmast in storage chambers and uses other chambers for nesting, bringing in dry plant material for this purpose. There are often mounds of earth outside the entrances to the burrow. It also makes larders of food in holes in trees away from the burrow. The shade is very dense under a beech tree in summer and it has been found that beech nuts hidden in caches by the yellow-necked mouse, and not subsequently eaten, can later germinate and help with dispersal of the parent tree.