Corrected entry: Near the beginning of the film, Margolo pretends to have an injured wing and Stuart takes her in. The next day when Mrs. Little and Martha go for their stroll, Margolo flies onto the roof to strengthen her wing. This is all fine and dandy, but how can an injured vertebra be strong enough to place pressure on it the next day? Wouldn't Mrs. Little have suspected something fishy at the sight of this?
Correction: She was actually faking it. Falcon revealed that when Stuart confronted him.
Corrected entry: When Stuart first gets in his brother's plane and he flies outside and crashes in the park the family runs to see if he is OK, but they forget the baby at home all by itself.
Correction: This isn't a movie mistake - it's a parenting mistake (a rather severe mistake), but character stupidity or errors by characters (unless they mess up the plot of the film) are not mistakes.
Corrected entry: When the Little's go looking for Stuart they leave the baby in the taxi.
Correction: Once again - another parenting/character mistake - not a movie mistake.
Corrected entry: If the Littles can hear Stuart and Margola speak, how come they can't hear Snowbell?
Correction: Because Snowbell never speaks in front of the Littles.
Corrected entry: Why would the falcon want the ring? Even if he cashed it in for human money, how would that have value to a bird?
Correction: It's for the same reason humans have jewellery: owning valuable things makes one feel important.