Bird is the Word (Episode Three)

Summary
Phineas and Ferb decide to build 'the ultimate birdhouse'. At the same time, Irving tries to teach David, September's four-year-old brother, that it's much better to be a kid than to always follow the rules.

Elsewhere, Doofenshmirtz invents a "Have Funinator" when he and Vanessa have an argument about whether or not her preferred junkyard hangouts and black clothes are good for her.

The Too Young Line
Irving: Aren't you a little young to be so.....never-broken-a-rule-y?

September: Yes, yes he is.

Ferb's Line
None.