I am just learning and currently only have some earthworms. But I can say that I read in a scientific journal that earthworms (nightcrawlers which is what I have) need a minimum of 10 cm of actual dirt to live productively in. If they have this much dirt they can perform off the normal duties that they do, ie breeding forming stable burrows etc. So that is what I have been doing and they seem pretty happy cause I saw a pair maiting and I assume that they wouldn't do that if they were dying. Also earthworms like to feed from food that has not been burried.

Eventually these worms are going into the garden and I will get redworms. The redworms don't need that deep layer of dirt and they like to feed from burried food.

If the earthworms are trying to escape, maybe it's cause they need soil or are hungry looking for food. Like I said, I dont have a lot of experience though, so best of luck.