Why we need them...

All life forms have some role to play in their ecosystem. For an example....animals and insects who eat carrion keep the environment cleaner, bees and butterflys pollenate flowers and trees. Snakes keep fast breeding rodents under control and trees provide shelter and food. Bats both pollenate some plants and control insect populations....it all goes on and on in a very complex way. The distruction of a single spieces can have an effect ultimatly on the entire ecosystem.