It is Myotis lucifugus , the brown bat , which lives in the United States, Canada and Mexico. This small flying mammal, with nocturnal habits (the epithet lucifugus means 'that flees from light'), usually lives near streams or lakes, and no one surpasses it as an insect hunter, since it is capable of catching 1,200 mosquitoes in an hour in the dark . It is guided and hunted by echolocation , which implies that it uses a kind of natural sonar and emits ultrasound that bounces and allows it to detect objects and potential prey around it. It normally produces these ultrasounds about 20 times every second, but the speed of the impulses rises to 200 per second when it attacks flying prey.
The heart of this bat is also very sophisticated. It can beat at an extraordinarily slow rate, of only 8 beats per minute, while it is hibernating (that is, from October to April). And although the usual thing is that while you are awake your heartbeat is around 100 beats per minute, sometimes it accelerates until it reaches no less than 1,300 beats.
