I have 7 Black Kuhli Loaches, small just purchased 3 days ago from a local pet store.. They are healthy looking not pale or having any spots.. I was just wondering if it is normal for them to constantly dance the glass? I have hiding spots for them that are grasses, coconut shells, and logs. I know they are sensitive to weather, at least my older albino one is. But the first day they hid, now they are just dancing and dancing.. Tank is clean, no debris, I have a canister filter that is cleaned regularly. I just want to make sure they aren't stressed. I also throw food in after lights off before I go bed, haven't seen them go for it. I've put flakes, shrimp pellets, bug bites. Any suggestions are greatly appreciated! Thank you!!!