Predators are in no way invincible. Watch either Predator movie.
Aliens are in no way stupid or less smarter than Predators. Watch Aliens.
Aliens would sacrfice their own to protect the nest, defeat their opponents, and ensure their survival. Watch Alien: Ressurection.
Even though Aliens don\'t emit heat, Predators have different visions to see them, clearly. Play A vs P on the PC.
When Facehuggers impregnate, the embryo can control the host. Watch Alien:Ressurection and play A vs P in the arcade by Capcom. Best A vs P game, ever.
Eventually, Aliens would figure out their opponents and just swarm them. The Predator wouldn\'t be able to take them all out.
Predators are not invisible.
Aliens can sense prey and can even read minds.
Aliens are definitely superior to Predators and Humans, but not in a 1 on 1 on 1 fight.