Here are 20 examples of biodegradable materials:

1. Wood
2. Wool
3. Paper
4. Eggshells
5. Fruit peels
6. Sawdust
7. Some detergents
8. Waste from the sugar industry
9. Waste from the wine industry
10. Green garbage
11. Food waste
12. Biodegradable plastics
13. Human waste
14. Manure
15. Sewage
16. Slaughterhouse waste
17. Dead animals and plants
18. Hospital waste
19. Cardboard
20. Leaves

These materials can be broken down by microorganisms such as insects, bacteria, or fungi. Biodegradable waste is typically waste originating from plant or animal sources that can be degraded by other living organisms.