Ant frass? in shower cubicle
I have this black powdery substance that appears in my shower cubicle (see pictures). Given that there are small ants running about I assume it is ant frass?
- The ants seem to be coming out of the small holes in the grout (see pictures). Do I need to have all the grouting redone? Or can I just DIY fill in the holes?
- Do I need to have someone check if there is water damage behind the tiles from water leaking through the small holes in the grout?
- Are the ants harmless to the structure? Do I need to do anything about them / pest control etc?
