I have a frogspawn that I've had for 3 years. It has grown from almost nothing. It had 3 tiny heads on it when I rescued it from a friend. It now as ten big beautiful heads but in a few of the heads a bubble has developed. It is noticeable even when the lights are off and the heads are closed almost all the way. Everything still opens up real well but It doesn't look right. What could it be?