My wild type actually got one in his mouth once, but he wasn't able to swollow it becuase the Otocinclus have tiny hairy spines on them, so he pretty much got stuck in his mouth and thank goodness too becuase I love these little fish! They try alot to catch them, but these little fish are very, very fast and usually can detect the Axolotl before it attacks. Actually, these little fish are so friendly that when I clean the tank and i have to move them out, most of the time I just reach in and pick them up with my hands! They don't try to fight or flee, they sort of just vegg out on the plastic plants and I just reach in gently and pick them up with my fingers and put them in a container till the tank is clean. It's better for me to do it this way than to use a net because the net can damage them. They don't get more than 2 inches I think and they are constantly at work to keep the tank clean. I will never use any other cat fish to clean a fish tank ever again other than these little guys. They're great!