I have a 10" male Midas that every spring is ready to mate and will attack my hand in the tank. I put on heavy gloves during this time to clean the tank. He will latch on and shake like a pit bull. Thankfully this only lasts for a short period of time and I can tell by the way he acts when he is going to do this. A LFS has a breeding pair of Dovii with the male being around 16", it has a real mean disposition and is a total glass banger. I would be afraid to stick my hand in that tank even with gloves because it has got some teeth.