Here in CA, we have to get tags, but can also hunt them yearround. The problem is that even though the state allows you to hunt them, you still have to find a place to do it. I hunt on BLM land, but the pigs are pretty smart and generally hole up on private property.
You don’t even need a license in Texas if you are hunting with a land owner on his property that he is trying to clean up. I’m not sure the requriements the land owner has to use with the State.
I think all game animals get pretty smart about that. I used to have my best luck with rabbits hunting right along the outside of the state park boundaries, where they were relatively easy to approach. And everyone knows how docile the wild ducks act, when they are on a pond where they can't be hunted.
Mourning doves in my back yard aren't afraid of me, but just try getting close to one out in the wild. They usually light out 100 yards ahead of me.