When an animal scavenges, it looks for food in garbage or in the remains of other animals. It can also mean to search for things that have been thrown away or left behind.
Scavenging for food is a way for animals to survive, but scavenging for things can be seen as dirty or desperate.
Examples:
The vulture scavenges for food in the desert.
She scavenges through the trash for something to eat.
The raccoon scavenges for food at night.
The hyena scavenges for leftovers from other animals.
He scavenges through old boxes for things to sell.
The seagull scavenges for food on the beach.