Chiseling out old plaster/tile in below grade shower, pockets of ants...
 

South Florida resident. Update from my original post here - http://www.diychatroom.com/f80/remov...d-help-148642/

I bought an air chisel and was wacking away at the plaster and tile in the below-grade portion of my shower. I had assumed that tthey went below grade and did a layer of concrete around the below grade area. However as I was chipping away on the exterior facing wall, out came a mountain of ANTS! I quickly grabbed some killer/shield in the area (RIP ants), and chaged from the exterior wall to the wall adjacent to it. A few wacks later... another pocket of ants! It still seems like there is a solid surface behind the plaster, but somehow ants have gotten through and are living there.

Pictures: http://imgur.com/a/hwyIy

My question is what does this mean, and should I adjust my gameplan here? My plan was to use a shower pan liner and then use thinset mortar..., and tile over that. Is this not doable now?