Yeah cats in heat can make noises that would make the devil himself shiver. I remember a couple of cats getting romantic right over my head one night as I was coming out of the barn in the dark. It was pitch dark once I turned the tractor headlights off. I didn't have a flashlight and was pressed up against a haystack on one side and hay wagon on the other with the cats right above me. I had to squeeze through that narrow tunnel for about 20 feet. I fully expected to get my eyes clawed out any second but covered my face and charged under them with no damage done. Weird sounds for sure!