Scavenge (verb)

1. To search for and collect discarded or refuse material.
2. To search for food or other necessities in a hostile environment.

Origin:

Late 16th century (as a noun denoting a person who picks up refuse in the streets): from obsolete scawage (from scaw, of unknown origin), later reinforced by scavenger.

Examples:

1. The dog scavenged for food in the garbage.
2. He scavenged for scrap metal to sell.
3. The survivors had to scavenge for food and water.
4. The birds scavenged for carrion.
5. The city had a problem with rats scavenging in the streets.