Construct "Weapon Modification" is this considered a Natural Attack?

[olePigeon]

Suppose you replaced a Homunculus' bite attack with a tiny sized flail using the Weapon Modification construct option in the Ultimate Magic book. Since the bite attack was its natural attack, and it is now a flail, is the flail considered a natural attack?

Can the monster now take the Improved Natural Attack feat with the flail?

[Shifty]

I say no.

Natural attacks are defined as hooves claws etc per the primary/secondary table.

It's now an armed attack.