Years ago we had a problem with two species of ants here in the People's Republic of Maryland--sweet ants and carpenter ants. We tried everything we knew to keep them out of the house, but nothing, including a very expensive exterminator program, worked. Then I tried a diluted solution of Avon Skin So Soft, sprayed it around the foundation, and that was the end of the ants. Apparently, ants, and many other insects, breath through their thorax. The vapor from Skin So Soft was such that when they approached it they could not breathe. Been using it every spring since then and the problem has been solved--bugs are gone.
Unfortunately, we now have a problem with squirrels, which eat everything in site, especially if the item has some sodium content. The only thing that repels squirrels is lead fired from a rifle or shotgun barrel. Just a few years ago I had my car's brake line gnawed by a squirrel, which damned near caused an accident. I put on the brakes and they went to the floor. The mechanic showed me where they had been gnawed through. We've also had wiring, plastic gas cans, gas can caps, flower pots and a host of other things gnawed by those nasty tree rats. I'm sure that if your keyboard were stored in a garage, shed, etc.., that was not squirrel proof they would eat the damned thing down to the keyboard stand.
Gary