The beetles do not eat the wood it is their larve that do that. The beetle once mature makes a flight hole in the surface of the wood that is the tiny holes you see and they come out to lay their eggs in nearby wood. Then they die off. So if you have seen fresh dust or any beetles dead or alive about then there is a good chance that eggs have been layed in surrounding furniture and floors etc... They will hatch into Larve and start to feed off you're wooden bits n pieces eventually a year later they pupate just under the surface of the wood and change into an adult beetle, emerge through a flight hole and the cycle starts all over again... and again...and again....
If you suspect infestation then get all areas sprayed before it gets out of hand. you can buy sprays etc. from most DIY chains and Timber Yards Just follow the instructions to the letter and well ventilate or call in a company.