Give them a few days and they will be back out, they aren't sick, just a little scared. They have just been taken out of a tank, into a bag and (possibly) taken on a car ride, all before being put into a new, different environment, which is all pretty scary for a little fish. In a few days their confidence will grow and they will start to come out. So long as you followed all the rules and let the fish acclimatise when you put them into the tank and didn't just put them in then they should be fine. Hope this helps. Took my Gouramis a week to stop hiding away.