Chicken Little

In the town of Oakey Oaks, the citizens are thrown into a panic when Chicken Little sounds the schoolbell, proclaiming that the sky is falling. Leading the townsfolk to the village square, he claims that a piece of sky shaped like a stop-sign hit him in the head. However, there doesn't appear to be anything there, except some acorns. Chicken Little's father, Buck Cluck, assumes that maybe it was just an acorn, and that his son over-reacted. Buck apologizes for the 'false alarm,' but the townsfolk are not quick to forgive Chicken Little.A year later, Chicken Little is still ridiculed for his 'false alarm.' At school, tries to rely on his friends Abbey Mallard (considered an 'ugly duckling'), Runt of the Litter, and Fish out of Water.At school, Chicken Little and his friends endure a game of Dodge Ball, before being pushed around by Foxy Loxey, and her friend, Goosey Loosey. This leads to Chicken Little accidentally pulling the fire alarm, which leads to his Father coming to take him home.Chicken Little is still hurt that his Father seems let down by his previous actions, and decides to play for the school baseball team. However, his plans to make his Father proud are sidelined when Foxy Loxey becomes the team's champion, leading the team to the final game of the season.Chicken Little is called up to bat, but only after the roster is almost out of players. Everyone mocks Chicken Little, until he makes a surprise hit that stuns the other team. Chicken Little ends up winning the game, and it seems that his Father is finally proud of him.Later that evening, Little stares up at the sky, when suddenly, a star seems to plummet into his room. After recovering from the shock, Little is terrified to see that a piece of the sky has plummeted into his room...shaped like a stop sign! Worriedly, he calls his friends over, and they realized that the object appears to mimic it's environment. As Fish examines the back, a button causes the thing to hover. Fish happily jumps on it, and it flies up into the sky.Little, Abbey and Runt follow Fish's position to the baseball field, where suddenly, an alien spacecraft appears, out of which appear 2 alien creatures with tentacles and 3 glowing eyes. As they leave, the three enter the ship looking for Fish. Along the way, Little finds a floating orange mass of hair, that seems to sprout an eye. After walking away, the thing then sprouts 3 eyes and limbs, and secretly follows the group.The group eventually finds Fish, but Runt finds something even more terrifying: a map of their galaxy, with numerous planets crossed off, except for the next one: Earth! The group then rushes to get out of the spaceship, only to encounter the tentacled creatures that then give chase.The group rushes through town, intent to ring the schoolbell and warn everyone. Chicken Little manages to make it to the schoolbell, but stops when he remembers the humiliation he endured after his last false alarm. However, hearing his friends panicking as the aliens draw closer, he rings the bell. The sound causes the aliens to quickly retreat to their ship.The townspeople then follow Chicken Little, Abbey and Runt back to the baseball field, only to find nothing there. Buck also arrives, and the townspeople's mood about Chicken Little winning the ballgame that afternoon now turns (again) to annoyance at what seems to be another false alarm. Chicken Little tries to convince his Dad that it was real (along with his friends), but Buck admits he doesn't believe him.

Question: What does Chicken Little ring to warn the townspeople of danger?
Answer: The school bell.