My guinea pigs haven't figured out how to go down a ramp. Or up, for that matter. We have placed enticing treats down the ramp, and so on and so on, but no.
So what do we do? They have loads of exercise, petting and they have a roomy top bit, with a lot of space for tunnels, toys and so on. They also go out in the run often, but not recently due to terrible weather and no run cover. I'm thinking pulling up the ramp so there's no danger of them going down, if they work out how to (!) that is, and not coming up to their warm bedroom and food, until we find them hours later. Although it won't hurt them, I am definitely PFGPs (is perfect first guinea pigs a thing?) so 
Is this normal? Both of the lads don't seem to be the brightest. Their wheeking and furryness has won me over to guinea pigs already.