Why are my snails all hibernating? Assassins, nerite, apple!

[kenshi64]

I have three different snail types and all of them are acting weird! I don't know why! I used peroxide accidentally in the assassins tank and they seemed to die but when disposing I noticed their trap doors were shut! So I put them back!

My apple snails started acting weird after being in a tank where I was dosing mebendazole to deworm. But the nerites had no reason!
All of them are just shut in their shells at the bottom! What's going on with them?

[Arron Miyuki]

Its probable that the chemicals did some harm to them OR you have too much snails and too little food for them (Nerites) and hence, they fall off due to lack of energy and to try to prevent predation, they keep shut.