What is this? Please Help.

[ksbhondaracedr8]

I have a 8 gal. Bio cube. Set up 3weeks ago. I was looking in it tonight and I saw an animal that looks like a white snail w/o a shell. It has a red dot in the center of its back. It is about the size of an eraser head. If you want to see a videoo of this creature please emaol me at Bridges_k@students.lynchburg.edu, I will email the video clip to you so you may see. Please help me.

I have no photos but i did get a video. If you know what it is please tell me!