Thanks everyone! I have snail pairs in 2 of my tanks and only 1 in my smallest. I am into betta keeping and have all small Fluval tanks (2, 4 and 5 gal). They are all planted and need some algae eaters. I bought "zebra" snails because I know they won't get as big, so 2 may be too many in the 4 gal and 5 gal tanks, IDK. All but one of the Fluvals have the top intake so I can not lower the water level too much....about 1" from the top at most. They do have lids, but all have openings to allow for light penetration. Not sure if the snails will call across the top and out the opening or not, but I will keep an eye on them. If I read my research correctly it does take a male and female mystery to breed. Is this correct? Will the females still lay eggs if she has not been fertilized? I have not clue of the sexes of these snails! LOL... And maybe what I read was incorrect. I had been reading up on zebra snails and have had to switch course midstream. Any more info anyone can provide would be appreciated. These are my first snails....besides some red ramshorns that I wish I'd never gotten! I already have tiny baby's from them...