A while back I made a post about how Brahmin were irritating and went in areas they should stay away from in settlements. They were constantly getting in the way. Someone made the suggestion about using feeding bathtubs to gain some control, although it be minimal, over them. And I did use them. But I noticed a catch. It would only work for non-pack Brahmin. And it seems for some reason there's a pack Brahmin that keeps on getting spawned inside a house in Sanctuary Hills in my game. Always in the same house, and can't get out of it. I better start watching where I step when I plan on going inside it, sure looks like there's going to be a lot of crap laying around.

Ah, Trashcan Carla's pack. Annoying beast.

One thing to note is that if you have blocked any of the road into Sanctuary, the pack's path is disrupted, and it tries to find an alternate route. If that route is closed off, they'll pop anywhere trying to meet up with Carla (who usually stands in the road next to the yellow house).

I had to change my wall with the door to a gate, and this fixed the problem, so you may need to do a little redesigning.

At Starlight Drive-In I built a fairly large brahmin pen with two Feed troughs. With a gate of course. A brahmin showed up even before I completed the pen, and I made sure to close the gate when I was done. But thereafter, EVERY TIME I go to SD-I, I find that brahmin wandering around by the food stand area. At nightfall, it heads for the pen, but during daylight hours it is always out for a stroll. (And probably leaving fertilizer wherever it goes.)

Why even build a pen if it won't keep the enclosed animals inside? Aesthetically it's the logical thing to build. But in practice? Waste of materials.