O, btw, I grew up in the country. Spent several years on the sheep farm. Interestingly, the herd dogs use the same “signal” mechanism to move sheep. Rather than run around and bark, they get in “predator” pose and the sheep move accordingly.
Interesting to watch low-power energy, i.e. “signals”, accomplish work.
Yes, border collies. The good border collies complete the work loop (move sheep) with minimal expenditure of energy. One would merely raise an eyebrow and the sheep got the message, and moved. Very impressive.