I was changing up my sump and noticed a ton of these in the rubble chamber. They have heads that extend from the ends of the tubes and resemble fester dusters. However, the "tubes" are soft rather the hard like feather dusters I have seen. By a ton, I mean there are at least a few hundred of these things in there. They seem to be confined to just the rubble chamber. Anyone know what these are?? Should I be concerned?