I thought my tank was mantis free about 8 months ago when I saw one lurking around. He went into an easy to reach rock and made a quick exit thanks to me. Then tonight as I was going to turn off the lights I saw another one!!! He's about 2 inches long and little thinner than a pencil. All I can think is that he got into the tank as larvae and grew up in it. I get my water from the same area that I snorkle for mantis. Crazy!!! Anyways, he'll be up for sale when he's caught. I will also trade for him as well. And of course, I can always get macro algea if anyone wants some of that.