Scavenger

scav‧enge [intransitive and transitive]
1.if an animal scavenges, it eats anything that it can find:
Pigs scavenged among the rubbish.

scavenge for
rats scavenging for food

2 if someone scavenges, they search through things that other people do not want for food or useful objects:

There are people who live in the dump and scavenge garbage for a living.

scavenge for
Women were scavenging for old furniture.

—scavenger noun [countable]
Foxes and other scavengers go through the dustbins.