It would help if you had a couple of close-up clear pictures of these things. Put a few in a dish of very shallow water and get a few good sharp pictures. I suspect they are planarians commonly called flatworms. Planarian, any of a group of widely distributed, mostly free-living flatworms of the class Turbellaria (phylum Platyhelminthes). Planaria is the name of one genus, but the name planarian is used to designate any member of the family Planariidae and related families.

Last edited by Bill Cody; 09/14/18 08:13 AM.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management