Following a slime trail is also part of the hunting behaviour of some carnivorous slugs. Body mucus provides some protection against predators, as it can make the slug hard to pick up and hold by a bird's beak, for example, and the mucus itself can be distasteful.
1 Push button: The WPS button is either on the product or a clickable button on a wizard or utility screen.  Personal Identification Number (PIN): The PIN is either on a product label or can be viewed on a wizard or utility screen.
The WPS PIN is displayed on the LED screen of the printer when you trying to wirelessly connect your computer to it. This has nothing to do with your router. If your computer has located your network printer, then it will ask you for a WPS PIN.