Know better - Tradução em português

Hi there!!

I was reading a children's book in which a man, who has a vegetable garden, has his vegetables stolen by funny bunnies, but the man, who has never eaten any of his vegetables, doesn't know what's happening to the vegetables. Then the author says something like this: The man doesn't know where his cabbages, lettuces and carrots have gone. But we KNOW BETTER!! Don't we?"

I'd like to know what does "KNOW BETTER" mean in Portuguese!!! (I wish I could have the translation into portuguese) 'BUT WE KNOW BETTER'

Thanks a lot!!!!