We independently verified the actual mouse-nature of the songs by performing a Spontaneous Audio Performance Test (SAPT) with a feline experimental audience.* Sure enough, four sleeping cats roused, lifted their heads, and twitched their ears while the songs were played. One actually rose to a standing position. The subject felines failed to respond to the recorded sparrow song.
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* No animals were harmed in this experiment. All research animals involved in this experiment receive the highest quality of care, including personalized feeding and support by a trained post-doctoral biologist and her aide; free access to legal counsel and representation; and consultations with a high-quality veterinary facility.