This is a biology worksheet all about it hope this helps
I believe there is a pill for that. I think vets can do it too.
If the web happened to look like this one I attached then the anwser would be shrubs. If you take a look at the arrows the shrubs energy is moving to rats, insects and lizards which in turn feeds the coyotes. The starting point is shrubs and in general most food webs start with plants.
I attached the answer, but you picture is empty.