https://en.wikipedia.org/wiki/Etruscan_shrew
- the smallest known extant mammal by mass
- high surface area to volume ratio; needs super fast metabolism to avoid hypothermia
- resting heart rate: 25 beats per second
- eats 1.5 – 2x its body weight per day
- will torpor if it gets cold
- warms itself back up by shivering at 58 muscle contractions per second, thus heating itself 0.83 °C per minute
- they make chirping and clicking sounds
- groom themselves constantly when not eating
- can hunt prey of insects, larvae, worms, etc as big as themselves
- Mothers guide blind babies in a train of babies holding each other's tails (caravanning)
