Continuity mistake: Right at the beginning of the movie, when Scrat is looking for his nut, there are no teeth marks where he stuck his teeth in to climb. (00:01:35)
Continuity mistake: When the anteater is telling the kids to look at Manny because they'll probably never see another mammoth, you can see Manny's shadow on the ground and it's facing forward, but when the camera switches to facing Manny he's facing sideways. (00:16:05)
Continuity mistake: When Scrat is trying to get the acorn from under the ice, he has 'normal' teeth. He then bites the ice and has longer teeth. (00:18:00)
Plot hole: After Manny has agreed to go with Ellie, Crash and Eddie, he says "Ellie can be the mommy." He said Ellie's name, but she had never told him, nor could he have heard it when Eddie was talking to her. (00:22:45)
Suggested correction: Manny would definitely have been able to overhear Eddie calling out Ellie's name. As Ellie went to have a word with the possums, it's not like they went somewhere else, they just turned away. And Eddie wasn't precisely quiet.
Manny was also having a discussion with Sid and Diego so he wasn't paying attention to the conversation where Eddie said her name.
You don't necessarily have to be paying direct attention to a conversation to be able to pick out words.
I agree. Even if Manny wasn't paying attention, he still could've heard Eddie saying Ellie's name.
Other mistake: Watching the green fish monster closing up to Sid and Diego, viewing the monster from underneath it, it would have taken approximately only one second for it to have reached them in the rate it was displayed traveling at (considering as of the end of that shot). But it only reaches them about eleven seconds later. (00:31:05)
Continuity mistake: As Sid says "Yeah. She's tons of fun and you're no fun at all", Diego is on the right side of Sid (from Sid's point of view), standing relatively close beside him. Immediately in the next shot, when Sid finishes off by saying: "She completes you", Diego no longer can be seen beside him. (00:34:45)
Continuity mistake: In the scene where Scrat gets attacked/attacks the piranhas, the acorn gets swallowed by a piranha on the right, after all the fighting, Scrat jumps on a piranha on the lower left, which spits out the acorn. (00:35:20)
Continuity mistake: As Manfred and Diego tells Sid to stop singing the vultures' song, Crash and Eddie are standing upon Ellie's tusks. In the following shot, the possums are not there. (00:58:35)
Other mistake: Just after the valley floods, Manny is seen pushing a log to pry the rock out blocking Ellie's way out. You can notice that Manny is pushing it the wrong way. (01:08:40)
Continuity mistake: Near the very end of the movie, we see that Scrat's acrorn holes as he goes up the iceberg wall are in a fairly straight line. However, when the ice begins cracking, the cracks follow the line of holes which are now no longer in a straight line but very jagged. (01:13:05)
Plot hole: At the end of the movie, when the water drains away, there would be no way for a) the amount of water to drain away that did and b) for the mammoths that came through to be completely dry. (01:16:20)
Continuity mistake: In the first 'Ice Age' Diego isn't afraid of water (in the beginning he chases the woman and the baby through the river before she jumps off the waterfall and never shows any fear) but in this one he suddenly is. It's not like that he is just afraid of swimming because in the second movie he shows fear anytime when he touches water.
Other mistake: During Scrat's encounter with the rotating ice slab, he jumps three times in the middle of the slab and falls through. He should have jumped on either end of the slab. Also, he fell through the ice standing up, and in the next shot he is upside down, pushing up on the ice slab.
Continuity mistake: At the beginning of the film you'll notice that when the blue creature from the ice chunk dives back into the water he has a tail fin. When the creatures attacks Manny and his gang and Manny shoves the creature off it dives back into the water again without a tail fin. Then at the end when Manny is attacked for the last time the blue creature has its tail fin again.
Other mistake: After the "boat" is released from the rock, it glides past the nest where Scrat was before, yet the waves created by the massive "boat" would capsize the nest. The "boat" moves by without creating any wave.
