Trying out our BMC's

Hi all, i have the the male and 2 females left with me after Troy left on friday, what a big week getting used to the BMC's and there style of working. They were very impresive striat up, went to the lead on mob of cattle and bayed some hogs first go. They have alot of natural instinct that seems hard to turn -off, yesterday i let them out to have a run and they buggered of and i found them baying my brood mares out from the house. Bloody tough to, took "Crush" with me all day in back of ute checking waters around station, got late in afternoon and thought i'd let him off for a drink (bloody hot day), nothin, straight past water trough to work cattle.
Starting to wonder if this is a lack off handling at young age or our BMC's so driven by instinct that it is something i need to let them have but just need to be able to get a handle on.
Cheers
Baden