skullcap slug spawning

so i got up this morning took a shower and went and stared at my tank for a few mins before i leave for work and this is what i saw
http://s1263.photobucket.com/albums/ii634/brijesh0789/?action=view&current=4a77cece.mp4
it looks like a few of my skullcap slugs decided it was a good time to spawn. or at least i think thats what they're doing i figure if they were just eliminating waste they would only squirt out 1 or 2 puffs of "waste" but this went on for several minutes

 

oh and you'll have to full screen it to see it clearly

 

Stomatella snails?

Mine do the same thing some times, usually when I leave the pumps off and turn the pumps back on they spawn, little wisp of smoke is what it looks like to me.

I am sure you hermits are loving it, numm.