At my gliding club there is an older glider with a large toggle switch on the panel. That switch is labeled "BUGS". Always amuses me...

The "BUGS" switch is an input to whatever that glider uses for a flight computer. A single bug splat disrupts the laminar flow and significantly reduces the performance of the wing in that spot. Enough splats and you have to let the flight computer know that the performance of the glider has significantly decreased. In practice that affects things like the final glide calculation. Without the adjustment you might think you have gained enough altitude to get back to the gliderport without having to climb again, but you could end up a bit short.