Tiny, thin, blood-red worms can often be found in ponds and pond filters. Generally called bloodworms because of their colour, these worms will not harm any fish or animals in the pond.
There are two types of bloodworms that look similar. One is midge larvae or Chironomidae, while the other is an adult worm in the Polychaeta worm family, according to ImmunoCAP.
Some people can develop allergic reactions to touching dried, frozen or live bloodworms. Symptoms include itchy skin and breathing problems. Wash your hands after touching them.
Bloodworms help to control decaying food and plants that can sap oxygen from pond water. They can help keep pond water healthy enough for plants and fish to thrive in, according to All About Worms.