Question

this animal converts dead leaves into natural fertilizer and makes the soil fertile

Answer 1

when the animals eat the dead leaves and the digestion take place. After digestion excretory system take place in their body. When they remove the waste material from the body it means dung. Dung is used as fertilizer in many ways. So we can say that animals convert dead leaves into natural fertilizer and make the soil fertile.

Answer 2

Earthworms convert dead leaves into natural fertilizer and makes the soil fertile