Right, I'll explain it...
A Bugs Life is an animation, there are no human characters dressed up in little bug suits, they are cartoon characters of bugs.
Bloopers are a common feature of films featuring humans since they make mistakes. Animated characters don't make mistakes since they are computerised.
Therefore, the addition of bloopers at the end of an animated film is a clever piece of humour, they aren't real.
The person who asked the question didn't get this irony and therefore thought that the cartoon characters were humans dressed up in suits.
Were they just all dressed up in suits then?