I have 3 P. Bicolor about 15 months of age. I just noticed that they have started bobbing up and down like they are doing push ups. Is this something that they start doing as they mature? I have heard no calling so far, the average house temperature has dropped very slightly in the last month or so. 3 degrees maybe. I think it's endearing, however I would like to know more about what's going on in their frog heads if anyone has some insight. Oh btw, this usually happens when I have my face close to the glass watching their feeding antics.