I need help!

OK so my two kittens are completely fine eating fantastic and have both been neutured, only thing is that I've not seen either of them drink there water, I've taken there buster collars off to try and encourage them to drink, but they're not interested. Could they be drinking at night?? They seem fine though! Thanks.

Are they eating wet food? I know cats tend to drink a lot less water when they're on wet food because it's around 70% water. But do the tent test and pull the skin on above their shoulders. If it stays up or takes a while to fall down they are dehydrated and need fluids.

Also, how long have you not seen them drink water?