"Found while fishing a lake in NW CO. reeled it in"
A: "That is a Nostoc ball. The person who said bubble algae had the right idea, although that term is mostly used to refer to a marine alga, Valonia, which is unrelated. This is a mass of Cyanobacteria (formerly called blue green algae), held together by mucilage. It is mostly harmless, but do not eat."
This. Learning to sharpen your knife by hand is not easy at first, but it's worth it.
It detects the presence of an electric charge.