Pups are born dark brown, no matter what colour they end up later in life, their eyes, once open, are dark blue, this fades to brown or yellow by 2-4 months old. In a wolf pack, it is usually only the alpha pair who breed, the others will help to care for the young, bringing food and 'baby-sitting'. Wolves howl for a variety of reasons, which we do not fully understand. The howl carries for several miles and so advertises their presence and marks territory. Wolves also howl before hunting, and this may serve to excite the pack members and bond them prior to setting out.
Wolves have a double layer of fur.
The woolly underfur grows very thick in the autumn and helps trap air to keep the wolf warm, while the outer guard hairs repel snow and water, keeping the underfur dry. In the spring the underfur is shed and new guard hairs grow. Healthy wild wolves are very shy, cautious animals and have, over years of being hunted and trapped, developed a fear of people, avoiding contact with humans wherever possible. A wolf that attacks humans is usually injured or rabid. A large secure enclosure is needed to provide a naturalistic environment for the pack to interact in a normal way.