|I was digging in a flowerbed that the previous homeowners had neglected, trying to get it ready to plant. While I was turning the soil, I noticed that several times I came across some areas that have a purplish, almost cottony... clot of some sort, like a regular dirt clod, only purplish gray. There were no signs of any insect activity, but the clods were filled with what looked like tunnels of some sort. Any clue for me what it is? This is the first year we've been in the house, and I'd like to be able to head any problems off ahead of time. Thanks!