Nofence works because of the technology we've developed and because of natural herd instinct. Understanding how these work together explains why every adult in the herd needs a collar, and why Nofence works best with medium to larger herds.
This doesn't work the way you might expect. If the leaders stay within the boundary, the hierarchy shifts and new leaders emerge from the uncollared livestock. If the leaders cross the boundary to maintain dominance, the herd follows them out.
Either way, the virtual fence loses its effect.
Herd instinct affects how well Nofence contains your livestock. The system is designed for herds of 5 to 200+ head.
We don't have a collar sized for young livestock. While at foot, they'll generally stay with their mothers and don't need their own collar.