We will hear again from the book Wrong Tree by Jeff Wilson, this is a fascinating chapter about denning female bears, their cubs, just born,  and sometimes, also in there, the young from the previous year! Imagine crawling down a bear den tunnel;   "...I wormed my way down the tunnel on my elbows...I could hear a low buzzing sound, a bit like the buzzing of a swarm of bees...it was the sound bear cubs make when they are suckling."