helping a friend with cracked tile and discovered these little pockets of softwood “insulation” (it’s almost like acoustic tile but 3/4 wood type product)they use back when the house was built.

All we could find were little ants, not the big carpenter ants. Didn’t know what we call sugar ants could do this type of damage

The picture is not the best so this post may be a waste, but if you’ve ever seen insect damage like this what was yours.