Sorry if this is posted in the wrong place I couldn't decide where to put it. So outside out house we have a plastic bucket and it's been there for at least a few months with a few inches of water in it. Today I noticed there were little worm like things swimming round in side it. I put these in a jar and gave them to my nephew as he enjoys watching and feeding my fish. I did a google search and couldn't find anything to tell me what these things were. They are less than a cm long, have little worm like bodies with small circle heads, they are almost always floating at the top of the jar unless someone comes and disturbs the water in which case they wiggle down and then float back up to the top again a few seconds later. Could anyone tell me what they are?