Ranch Hands by the dozen

Not sure why but after playing for an hour or so today, one morning "Sim time" suddenly 12 Ranch hands beamed onto my property.  It was pretty funny, like the first one showed up and spawned a second, third, fourth and they just kept growing.  They stopped at 12 when I exited the game but they are running all over my place painting, swimming, playing instruments, everything but caring for the livestock.