I have 12 egg sack with white dots approx 3/16 wide by 1/8 tall that look like 1/2 of a bubble stuck to my tank. Some with as many as 6 and others with no white dots sitting on thhe bottom of sack. I have a variaty of snails, crabs and shrimp.
i had/have the same thing i think they are strombus snails...i am sure that is what they are. mine have multiplied many many times...a ton of babies in the overflow!! gotta love you snails getting it on!!
oh well more snails for you. mine took maybe 2 weeks or so to hatch. did you tank get warmer than it is used to? that is when mine get it on the most