Baby hermit crabs or predator?

[EG617]

I have a buncha white little shells all over the place they kinda look like white nassarius snails and before they use to only come out at night. My cerith snails laid eggs and had babies so i thought the nassarius snails did too. But when i look closer they werent snails they were some kind hermit crab babies and there also all white . Any idea what they are? and also all my certith and turbo snails are not moving and they are upside down its like there dead but when i put them right side up they flip over again. sorry i dont have camera so i cant post up any pics.

 

[Scottm]

Snails do that. As for the little critters maybe the hermit crabs had babies and your snails had babies and the little hermits jacked your little snails.