An Aldebaran mud leech is small annelid worm native to the mud of the Aldebaran system.

They can be used to treat insomnia as their secretions act as a natural sedative. In order to do so, one has to place one leech on one's chest and one on the abdomen an hour before going to bed.

It is necessary to sleep on one's back while trying this treatment, as rolling over might anger the creatures according to Doctor Phlox, who kept some Aldebaran mud leeches in his sickbay aboard the Enterprise NX-01. (ENT: "Anomaly")