It's All About The Ears
The pointy ears are like radar. They can detect everything outside the big clear glass known to them as the main lookout.
Every bird is accounted for and the odd mouse that is brave to go by the big glass gets accounted for as well. One is never sure when one might get outside so it's a good idea to have all birds accounted for. At least this what they say.
Other sounds within the big glass also is quite important. The rustle of plastic might indicate a bag of treats is near by. Don't want to miss out on that.
The most important one is however the sound of a can opening. The ears pick that sound up, even in the middle of a deep sleep.
The body jumps into action to the sound, usually in the kitchen, as always.
It's all in the ears.