If you swap a UFO with a wrapped candy, the UFO will create 3 wrapped candies that will not only do a 3×3 blast, but will also clear the candies in the rows or columns that they blast in. This depends on which direction the UFO and Wrapped Candy were swapped in. It is similar to the effect of a Striped+Wrapped combination.
If you swap a UFO with another one, or with a coconut wheel, both will activate. In the latter case, the UFO will shoot 6 wrapped candies.
If multiple UFOs are triggered at the same time, they are activated one by one.
If there is a UFO left on the board when the player completes the level, it automatically activates during sugar crush.
In Jelly levels, UFOs have a higher priority of shooting near the jellies.
It has a higher chance of shooting near blockers as well.
UFOs are very helpful, especially against jellies and frostings, but they have their limitations too. If the jelly you needed to clear was hanging somewhere on its own, then it can't be destroyed. The Wrapped Candies can only be deployed over occupied cells.