I always seperate them from the herd, either one at a time in the RP or one there and the other in this other little area out where we board if the hubby is there with me. When I notice their attention staring to drift back to the other horses we call it quits. Particularly the older filly - she gets antsy and goes to the gate and won't move, but just gives me her "mad ears" and stares at her buddies. I always get at least one more 'something' out of her before I turn her back out - make her back up so I can open the gate, pick up a hoof, something anything, but I do let her go. My little skitz will start to cry about it and weave and pace by the gate. Somedays we'll get 10 minutes of 'playtime' in and somedays they'll stick by my side for hours, mostly just hanging out with me petting them and rubbing all over them at this point.
So...am I right in assuming it is their attentions spans at this age (think 8 months and 18 months) and calling it quits or should I be asking for more - particularly with the older horse? I don't want them to be anymore herd bound than they already are (they are I admit it) but I also don't want to push them past their mental boundaries that come with youth? Any thoughts ya'll??