I just tried to listen to my cats’ heartbeats using a stethoscope. I couldn’t hear it; any heart sounds were drowned out by the sound of purring.
Instead, I spent the time petting both my cats at once. Not a bad way to hang out on a Sunday morning.
Of course, the logical conclusion is that since I can’t hear their hearts beating, I must have zombie cats. Those of you who’ve met my cats will realize that this explains a lot.