Snails and cycling?

I figured since the cycle process is so difficult on fish, it would be the same for snails, but they're popping up everywhere in my 75 gal, and there are ridiculous amounts of ammonia and nitrites in that tank. They hitchiked in on some plants that I put in there - I tried to pick out all the snails before adding the plants, but obviously missed some.

I am just confused that they are flourishing? Shouldn't the ammonia and nitrites be affecting them? Or are inverts not as bothered by such things? Is it cruel to leave them be, or should I be trying to rescue them from the tank and put them elsewhere? Ideally I do want snails in this setup once it's up and going, but I did not really expect that to be prior to the cycle completion.

Just curious...

Well that makes me feel better anyhow. I was worried that they were suffering in there, but since so many seem to pop up every day - I know they're breeding, so I couldn't imagine that they'd be doing so if the conditions were making them suffer. But I wanted to be sure. I don't know how i would have gone about getting them all out since there are so many and so many of them are teeny tiny, but I was willing to give it a shot. I'll leave them be since they'll probably aid the cycle with a little additional bioload. Not that they probably create much ammonia themselves, but I suppose it won't hurt.