Approx. weight limit of a generic suction cup?

One of my pet dwarf hamsters, Pepper, has a thing for climbing. She climbs climbs climbs up her cage, lets go, falls to the cooshy litter below, and does it all over again. Unfortunately she doesn’t really have much else to climb except for her cage itself, so I decided I’d make a rope ladder for her. I finished that, but was left with a problem: how to secure it. I decided to just go ahead and tie it through the cage bars. But she doesn’t exactly get the point, it’s essentially useless. I’m now contemplating getting a few suction cups from the hobby store, but I’m worried if this will work. I mean, sure a dwarf hamster probably doesn’t weigh that much, but if I were to put the ladder to something useful like up to one of the platforms where her food or water is stored, she’d probably be using it several times a day, and I can’t help but worry that I’ll have to re-fasten it too often.

So, I implore, should my brilliant plan be well-executed as it is, or will I have to resort to more permanent adhesives?

(For the record, I also plan on making a bridge out of hemp and popsicle sticks. I’ll let you know how that works out.)

I should add that the places I’ll be fastening it to are plastic. The hamster cages are part plastic, part metal cage.

A quick Google foundthis site. They claim a holding power of up to 125 lb. and I assume that’s for the 10" diameter. In that case they claim about 1.6 lb/in[sup]2[/sup]. A 1" diameter cup should hold 1.25 lb and the holding power goes up or down by the square of the diameter.