The Jack Russell is like a tiny, hyperactive bundle of mischief with a wagging tail and a bark that could wake the neighbors. Think of a small, furry tornado that’s always on a quest for adventure, preferably involving chasing things that may or may not exist. With a body that’s too small for its big personality and legs that seem to run on caffeine, it’s the canine equivalent of a coffee-fueled squirrel wearing a perpetual smile. It can sniff out trouble and somehow find a way to get into every nook and cranny in your home, making it part dog and part stealth ninja. Plus, don’t be surprised if it tries to outsmart you; after all, it's convinced it's the main character in a heartwarming Disney movie.