Also taken are crayfish, snails, spiders, earthworms, scorpions, leeches, millipedes, and centipedes. Green sea turtles have a variety of parasites including barnacles, leeches, protozoans, cestodes, and nematodes. Ducklings are dependent on animal matter such as insects, earthworms, leeches, midges and snails. The thick skin does not protect against bloodsucking "Tabanus" flies, leeches and ticks. Wet flies, known as streamers, are generally thought to imitate minnows, leeches or scuds. Walleye also feed heavily on crayfish, minnows, and leeches. Specifically, they have been noted to feed on crayfish, frogs, snails, salamanders and leeches. Examples in animals are more common in non-vertebrates such as flatworms, leeches, and brine shrimp. Oligochaetes evolved from polychaetes and the leeches branched off from the oligochaetes. Glossiphoniidae are the family called freshwater jawless leeches or glossiphoniids. Its ingredients include fluxweed, knotgrass, lacewing flies, leeches, powdered Bicorn horn, and shredded Boomslang skin. By morning they would be covered in mud and hundreds of leeches. They sail to the cave where she is hiding and rescue her but attract leeches. Waste material leeches underground, contaminating aquifers. Nevertheless, only a few cases of leeches transmitting pathogens to humans have been reported.