Every once and a while it is advisable to clean one's keyboard and mouse with an antibacterial cloth. We use our keyboards and mice non-stop and consequentially they are ridden with dirt, grime, and numerous bacteria.
I like to take an antibacterial wet wipe (squeeze out excess liquid if any, before wiping) and give my peripherals a good wash down once a month.
Remember, however, to disconnect your keyboard and mice from your computer and leave them disconnected until you are certain that there is no spare liquid left residing underneath the keys or buttons on your mouse.
I'd also like to address those who share their computer(s) with other people and recommend them to consider cleaning their peripherals more often.
Furthermore, if one is so inclined, they make disconnect their keyboard and vacuum between the keys to take out any unnecessary filth.