[goda90]

A reason I like to use for biodiversity is pests. Pests thrive off of human activity. They don't really need biodiversity to continue being around, because they have us. Getting rid of pests is hard, and totally annihilating them is very very hard. Really it's only worth the effort to keep the population low. Biodiversity gives us predators. Predators can keep the population in check. We don't have to put in the effort if there's enough predators to kill the pests themselves.

But our efforts to kill the pests can often harm the predators. The poisons we use might kill the predators too. The cycles of taking the pest population really low and then it jumping back up might leave the predators without enough food.

If you spray your yard for insects, the first things that will rebound in population are mosquitoes and flies because they eat us and our trash. Spiders and dragonflies will also be killed, but they'll rebound slower because their prey has to rebound first. Then what if you spray again before they fully rebound?