In my 75 gallon I have 4 female swordtails(well at least I think. One of my females is starting to grow a males tail) I'm not worried about that though. But one of my females keeps hiding behind the drift wood. Which is in the back of the tank and she won't move. I just got her maybe 5/6 days ago. She was perfectly fine. We have led lights that blow bubbles too and she'd swim with the other swordtails through them and just around the tank. But now she only comes out when it's feeding time. I know that when a pregnant swordtails is near spawning time she'll lay on the gravel or what and be aggressive and be very interested in food but I don't see a Gravid spot but she does have a big belly. Our last swordtail that did this died a few days later and I don't want that to happen again. Is she ill or being harassed? Please help