We are confident that this specimen is a rat-tailed maggot. A rat-tailed maggot is another name for the larvae of some species of hoverflies (maggots are the general name for all fly larvae.) Most rat-tailed maggots that our readers deal with are drone fly larvae. Drone fly larvae typically live in stagnant water with low oxygen levels and high organic content. The thin appendage that is coming off of the maggot’s body is not a tail, rather it is a tube-like breathing siphon that lets the specimen breathe while submerged under murky waters. Rat-tail maggots can tolerate polluted waters, so their homes are often pretty gross. They live in sewage lagoons, wet carrion (the decaying flesh of dead animals), open latrines, liquid cow manure, and toilets.
So, how should our reader deal with these maggots? Well, rat-tailed maggots are generally harmless, but we assume he would prefer they stop appearing in his toilet. Getting rid of these maggots is fairly easy. He will simply need to scrub out his toilet to remove any potential food sources. He should use a cleaning agent that is designed to kill organic matter and a pipe cleaning brush. Once the toilet is properly cleaned, there shouldn’t be any more maggots!