The leader of the gang

A week ago we got four tiny ponies to eat the grass in our field, they were such quiet docile creatures, after a few days this one showed its true colours and started bossing the others about.
Today he took it one step further and decided the grass was greener in the garden, while trying to catch him one of his mates followed.
All this happened at the time I was due to go for a hospital appointment. 
Panic, Panic time so had to ring the ponies owner to come to our rescue, shut the gates on the drive and leave them in the garden.
When I got back they had been returned to the field so presume they were caught ok and will now stay where they should be.