I don't keep Diplodactylus, but i know that D. vittatus has digital lamellae (can climb glass). I'd guess the similar species such as galeatus and granariensis may have these too. From my pics I've taken in the field, stenodactylus doesn't have these, but if everyone has a look at their open top tanks, they'll find a thin bead of lovely soft silicon in the corner. Plenty of clawed critters are capable of climbing up this.