My 10 gallon has been cycling for about a week and a half with 2 harlequin rasporas, 2 pygmy cories, and some hornwort. Both of the harlequins, and 1 of the pygmies are running up and down the glass all the time, but stopping to eat if I put food in. The other cory is acting normal. Why do you think they are doing this, and why not the one cory?