I have a couple of questions;
Is the coyote activity frequent?
Do know the route the coyotes take?
Is there lighting around the trouble area?
Can you find a hiding spot near the coyotes path that the wind is in your favor?
My suggestion is to just wait them out, and kill one without calling, decoys or anything. Sounds like things are going on that they are pleased with already.
After a few outings then start calling. My bet is that you can ambush them easily at first. It will give you good intel if u don't.
Once you call and fail it'll be a couple weeks before calling will work.