Grey dwarf hamster with white belly, lost pet

Yesterday around 3pm I realized my grey dwarf hamster with a white belly is missing. I last saw him near the Co-op on Fore Street in Exeter, darting toward the alley behind the Cathedral. He’s tiny, about the size of a walnut, with soft grey fur and a bright white belly. He has a distinctive notch on his right ear and a small white patch on his left hind foot. This little guy is my daughter's pet and means the world to us; I’m really hoping someone who found him kept him safe. If you’ve seen anything, DM me here or email [email protected].