As far as I know, the more worms the better! You should be glad you have good soil that attracts the worms. I would say they shouldn't be a problem.

I would think having a lot of worms would be a good sign that the soil is nice and rich or going to be soon.

Kat

There is concern that an ever increasing population of non-native worms (nightcrawlers, etal) are changing the soil structure of the Northwoods and will eventually change the trees that grow there. Your backyard shouldn't be a problem.

tj

I know I should be excited about my worms but I sure don't want those foreign worms eating up all the good stuff in my soil. Thanks tj

Actually, the worms aren't eating up all the good stuff, but, rather, they're improving the soil and making it fertile enough for other species to move in.

tj