The alien ticks are a race of insects encountered by the Destiny expedition during an off-world mission in an unnamed galaxy. They attach themselves to the back of the victim's neck and release a toxin which heightens negative emotions, manifesting them as hallucinations of the victim's worst fears. Any attempt to remove them causes them to burrow deeper while releasing a large amount of toxin, potentially killing their host. In this event, they move to someone else nearby after a short period. They can be sedated by Squiggler venom, which keeps them from reacting to attempts to remove them. (SGU: "Pain")
Various people experienced different hallucinations while affected by the bug's poison.
- Lt. Vanessa James: Having sex with Lt. Matthew Scott, after which she murdered him in a dispute over choosing between her and Chloe Armstrong.
- Dr. Dale Volker: Being trapped in increasingly small spaces.
- MSgt. Ronald Greer: Camile Wray and Dr. Nicholas Rush conspiring to take over the ship again, and being ordered to deal with them.
- Chloe Armstrong: Her father Senator Alan Armstrong.
- Lt. Matthew Scott: His son Matthew Balic.
- Dr. Nicholas Rush: Being trapped in a Nakai holding tank, followed by an invasion by the Nakai.