Sentence:  If we manage to keep track of a Bombus queen after she has left her feeding place , we may discover the snug little hideout which she has fixed up for herself when she woke up from her <WSD>winter</WSD> sleep . 
Meaning of the word marked with <WSD> tags:  the coldest season of the year; in the northern hemisphere it extends from the winter solstice to the vernal equinox