BATS may use 鈥渟tealth鈥� tactics to fool moths into thinking they鈥檙e still a safe distance away, when in fact they鈥檙e moving in for the kill.
As a hunting bat approaches its quarry, its ultrasound pulses get shorter, higher and fainter. Researchers had thought this was to avoid potentially deafening echoes, but James Fullard鈥檚 team at the University of Toronto have a different explanation.
The team recorded attack calls from an Eptesicus fuscus bat by training it to attack a microphone. They then played these 鈥渕oth鈥檚-ear perspective鈥� calls to other moths while recording the activity of one of their auditory neurons. As the bat approached, the neuron fired more rapidly, but in the final 150 milliseconds of the attack sequence it went back to firing as if the bat were 20 metres away (Journal of Experimental Biology, vol 206, p 281).
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