Continuity mistake: When Sid is relaxing in the 'goo' and has it splattered on his face (no-one knows what it is), he wipes his face off with Manny's trunk, none disappearing. In the next shot, the 'goo' has completely disappeared from Sid and the baby.
Continuity mistake: At the end of the movie, where Manny returned the baby, and received the talisman from the human, it was hung from Manny's tusk. As they meet Diego and walk away, the talisman isn't there anymore.
Answer: The sequels take place before he was frozen.
MasterOfAll
That's not true. If the movies made later were prequels, how would the characters all already know each other?
Good Lord, people are overthinking this, hahaha. It's a silly animated movie series primarily aimed at children. It's OK if the Scrat character doesn't have super-concise continuity. It'd be like getting upset over the Looney Tunes not having strict continuity.
TedStixon
That one scene is set much later than the other films. The sequels aren't prequels.