Flock of Wild Birds Birdhouse

I have the tree of wild birds. I did a few interactions with them then got a message that I can now buy the "Flock of Wild Birds House" in the build mode. So, I went into the build mode and searched for the house, as directed, in the Activities and Skills menu. It isn't there. I searched in Pets, not there. Is there a bug or am I missing something? Please help!