mine when its stressed turns a loive green color. I had two of them one was beat to crap other was the beater. Got both for price of one. 8.99. Im down to one . They get real real mean. mine loves to haras the fh thats got close to two inchs on him in size. I feed mine pellets. Mine since like i duno some time around jan went from inch in size to pushin the 5 inch mark.