Unwanted Visitors?

[BigTuna]

I tried posting earlier in another thread but wasn't getting any feedback. I noticed a couple days ago, completely out of the blue, that there were dozens of tiny 'snail-like' critters throughout my freshwater tank. I have not added anything in months. No new fish, no new ornaments. Any ideas what this can be? Is it a potential disaster that needs immediate attention? Any help is greatly appreciated.

 

[Nosphaer]

I think a picture or more precise description would help aid reach you more quickly, but I'm curious about this, so I wish you luck in your identification of the unknown guests. o:

 

[Man of fish]

Pictures may help.

 

[This Old Spouse]

Yup. Photos are the only way to ID the critters for certain.

 

[BigTuna]

I'll charge up my camera. Maybe I can get a pict up tomorrow after work. My backup digital camera isn't strong enough to pick up a clear image of the little buggers. I hope my Canon G12 can do it.