Earthworms have not been in a lot of parts of the planets until very recently, when humans reintroduced them. The reason you like the worms so much in your garden is because they're burrowing through the soil and finding bits of organic matter that have rotted. They are then digesting that and pooping it out in a new nutrient rich little broth. Because its carrying so much broken down organic matter is great for growing crops. And so worms are widely viewed as a great thing. But the reality is that in places that the orms haven't existed for 12 thousand years, other animals got a foothold and developed their own eca systems. And now, as the worms burrow