Puppy Pooping in Crate During the Day?

My 4 month old puppy keeps pooping in her crate whenever I go to work. She just scatters it everywhere and lays in it! She is locked up for 8 hours during the day, but I also lock her up at night. She doesn't poop at night. She's really good and holds it (sometimes doesn't even need to go in the mornings), but during the day she will poop a few times no problem. How do I get her to stop? I keep her on a walking and feeding schedule.