I put two barley straw bundles in my pond this week--in a very shallow area with some grass growing in it--so they couldn't blow around and sink deep enough that I wouldn't be able to find them. Two days later, they were gone. I have looked all over and cannot find them. I have minnows, small fish, a larger catfish, and some turtles in the pond. Any ideas what could have happened to the bundles?