It can tell them if other wolves were in the territory, if they were male or female, and how recently they visited. Less than one percent of sheep and cattle are killed each year by wolves. Loss of cattle to poisonous plants, diseases and poor husbandry account for more deaths. A few years ago 11 people were gored by bison in Yellowstone but the bison weren't given a bad rap. Wolves howl to communicate, advertise their existence, warn off intruders, greet other wolves, mark their territory, gather the pack or enjoyment.
Wolves also communicate by the position of the tails, lips, nose and ears.
Wolves live in family groups called packs. A pack is usually made up of a male parent, a female parent, their pups and a few other adult wolves who are the older brothers and sisters. The pack works together to hunt for food and to take care of the pups. An average adult female wolf in Minnesota weighs 60 to 80 pounds. Males usually weigh 80 to 100 pounds.