No,  not pigeons, rats, or raccoons.  Urban Animals by Isabel Hill (Star Bright Books, 2009) is about animals in architecture, and it works as an introduction to architectural terms (like keystone, column, and bracket), as well as an I Spy book that might inspire you and your kids to look for the animals in your own built environment (or in a nearby city; author and photographer Isabel Hill found all of these animals in New York).

I like the design details of Urban Animals itself:  Colorful cartoon animals correspond to the mostly monochrome architectural ones, and coordinating accents (photo corners on the detail shots, the hand-printed font used for architectural terms) brighten things up.  The rhyming text (it's all in couplets) is relatively utilitarian.  Here's a typical double-page spread:

There's also an Architectural Glossary at the back of the book, helpfully keyed to a line drawing of a city block; and a list of "Animal Habitats" that gives the NYC street address (as well as the architects and construction dates) of the buildings featured in the book.

It's interesting to think about why a particular animal might have been incorporated into a building's design:  the cow on the Sheffield Farms Milk Plant makes sense, and so does my favorite, the squirrel on the Kings County Savings Bank, but what about the alligator on Liberty Tower?

[Local folks, check out the National Building Museum's Calendar of Events for animal sightings in Washington, DC.  I'll let you know if we spot any more!]