Wild Tracks by Jim Arnosky is a book that my kids loved! It has some very interesting facts about different animals in North America and talks about how tracks change depending on what the animal is stepping in and what the animal is doing (running, walking, turning, scratching). It even discusses how some animals tracks may differ depending on sex and time of year. It has fold outs to reveal actual sized tracks to compare each animal track to size. Zoe and Austyn liked to compare their feet to each animal track. It was the most interesting and fun book we've found on animal tracks in North America. I hope you borrow it soon from your library and your kids love it as much as mine did.