Of course their sense of smell also tells them when food or enemies are near. That is one of the ways wolves communicate with their voices. Wolves don't just howl at the moon. They will howl any time of the day, but are most often heard in the evening because that is when the pack is most active. Sometimes it seems as if they howl just for fun.
Wolves also bark to warn other pack members of danger or to challenge an enemy.
They make a squeaking noise to call the pups and the pups' mother will whimper to calm them down. Communication is required to keep order in the highly social setting of wolf packs. EYES - Vision is most common within the pack. Wolves use visual recognition with fellow pack members very similar to our domestic dogs recognizing familiar faces. NOSE - Wolves identify individual pack members by urine and scats, commonly called scent marking.