Well, last year I was stalked several times by a coyote while either running with my dog or riding my ATV with the dog and my daughter. It took several encounters before I realized what was going on. At one point it kept coming up behind us on the trail and I repeatedly chased it away only for it to come back. It must have followed us for 1/4 mile. That was the first coyote I had ever shot. Up until that time I was against shooting coyotes and I explicitly told the two guys who I let hunt deer on my property that they were not to shoot coyotes they might see while deer hunting. That has changed now. I've lost two cats as well, although I can't be sure it was to coyotes.
Regarding this litter, I've seen one of the parent coyotes three times. It has a distinctive dark-tipped tail. The first time was the night before the discovery of the den. I didn't mention it in the original post, but I was in a tree stand not 15 yds from the den and called in that adult coyote. My brother missed. The second time I saw this adult coyote was two days after the den discovery. I was coming home from work and it ran across my horse barn field, less than 200 yds from my house. The third sighting occurred two mornings later around 6:15 am. I had just taken my dog out to go to the bathroom (on a leash) and as I was taking my boots off I saw through the back window this coyote cross my backyard not 45 yds from the house.
If humans were a wee bit smaller and dumber we would be on the menu.