I just had a female do that last week when I put a male in, it freaked me out to the point I pulled her out and made sure she was really a she. The only time I has seen that kind of a reaction was when my daugter had accidentally put 2 males together. Everything checked out so I put them back together and they were locked that evening. I just chalked it up to her being upset from me cleaning her tub beforehand ...

Neil