Question for management

In fact, I don't care what do my colleagues in the working time.
Because our business is not good.In general we have not much things to do.
I hope they can control themselves and don't make any mistake,it is enough.And don't let my boss see they have nothing to do.
But I always was scolded by my boss for they are gossiping with somebody in somewhere.It makes me very angry.When I tell them it.They seem not matter it.
So I begin to arrange them something to do to kill their time and prevent them to gossip.But they think it is not reasonable to arrange something to do for them.
I wonder what can I do when the business is small,even nothing to do.