They have the fastest hearbeat (1,200 per minute) and one of the shortest life spans (11 to 13 months) of any mammal. They don't sleep fore more than a few minutes at a time, and they never go into torpor or hibernate. . . . [T]heir brief life is spend in nonstop foraging.
They have to eat every 15 to 30 minutes day and night to stay alive; a full hour without food means death. They can survive temperatures of -37 degrees F because they build tunnels under the snow, but they cannot survive temperatures higher than 77 degrees F. They live in moist, boggy areas which are being devastated by global warming, as well as habitat destruction.
This was one of the most interesting articles I've read about animals in a long time. Please take 10 mintues and check out the article for yourself online. Pay special attention to the picture of the pygmy shrew (eating the yellow spider). Pictures are extremely rare and, in fact, I couldn't find any others on the internet to share. The pygmy shrew is the smallest mammal in the world. It weighs barely 0.07 ounces and fits comfortably on a thumbnail. Its babies weigh in at 0.009 ounces (that's nine one thousandths of an ounce!) Below is the link for the article.