In the warm roost inside a hollow tree

Welcome to your life as a vampire bat!

You are still somewhat young, though you are not a pup anymore. That is to say, gone are the days when your mother went hunting and fed you.

You have to hunt like your roost-mates (other bats) and consume at least half your body weight in blood every night.

Here is the catch: Feeding is not easy at all. After 60 hours of fasting, you will not be able to preserve your critical body temperature, lose about a quarter of your body weight and eventually start starving to death. You will almost certainly die after 70 hours without food.

"LIFE" shows how many hours you have left until the starvation.
LIFE is 45.