My mare that is now 8 used to buck and play when she had toooo much energy!
She would only need to find an excuse to play! Even though she could more on the delicate side, until today I ride her on a rubber pelham to be able to stop her if she decides to play (when she buck’s she grabs the bit and you have a hard time bringing her head up and stopping her!). She has gotten a LOT better as she started to get older.. she is a GREAT show jumper, very easy on the course and very honest! But she always needs a cooling off in a different place or when there is a lot going on!
If she is to full of energy I ware her out, she cant concentrate while she is full of energy, so i gallop her in a circle and little by little make it bigger as she starts to feel calmer, and I am careful not to let her head down! once she has let go her extra energy, we walk and cool off, and then begin her working routine! and by then if something attracts her attention, I draw it back by a turning her head, changing the pace or changing the exercise..
I think it is very hard for a horse to full of energy to concentrate!
As she gets older, the playing around gets less fun! But be careful not to introduce bad habits! rearing is a serious bad habit. if tension arises always go forward!
OPS! I forgot to say that we used to plug her ears so that her attention was not drawn away by just any noise! but now as she aged, she is SOOO much better! we don’t plug it any more!