The pygmy shrew (Sorex minutus) holds the title of the smallest mammal species in the United Kingdom. These tiny shrews typically have a body length of about 3.2 to 3.8 inches (8.2 to 9.7 centimeters) and weigh around 3 to 6 grams. They are recognized for their petite size, pointed snout, and voracious appetite for insects, worms, and other small invertebrates. Pygmy shrews are commonly found in various habitats, including woodlands, gardens, and grassy areas, making them a unique and fascinating part of the UK's mammalian fauna.