[TOMT][CHILDREN'S BOOK][1990s-2000s] I Spy-like Book with 100 Mice at School, Elaborately-Detailed Environments

A memory popped into my head of this children's book I really liked in the 2000s. It's a book with these elaborate landscape spreads that take up two pages (the cover is of a schoolyard I believe), and all of them are crowded with simplistically-drawn white mice. I think the premise of the book was either a search-and-find book (like I Spy) or a counting book. Each page was a different environment and I want to say that each one had 100 mice. Thank you to whoever knows this; I will love you forever!! <3