They make their outrun to the sheep. Once the sheep become aware of the dog's presence behind them, it's a term called "lifting" the sheep. The dog then fetches the sheep, driving them toward the handler. Sometimes they are asked to "drive" the sheep, pushing them upfield away from the handler and through a different set of gates. The dog has to crossdrive the sheep through a second set of gates and then fetch them back to the handler so they can be penned.
The dogs don't actually chase the sheep in the pen but gets them as close to the opening of the pen as possible without scattering them so the handler can get them into the pen. They normally use a crook or staff of some kind to guide the sheep in. And of course, it's difficult because the sheep, who are prey animals, are doing everything they can to avoid the danger.
Watching the dogs work was mesmerizing. I could have stayed all day and never got tired of watching them herd. They love it too. Their focus and concentration is on those sheep and doing what they do best. Here are some photos of these amazing and intelligent dogs.
Fetching the sheep
Sweet young girl waiting her turn
Crossdriving the sheep
Driving the sheep
Penning the sheep
Pure concentration while waiting their turn. The only other dog that was not a border collie was the sweet bearded collie named James.
James, 11 years old, waiting with his handler.
I can easily see how addicting this could become. Working with your dog while doing what he was bred and loves to do. Simple words for such a satisfying and fulfilling activity.