Hi matimage! I don't know which amphibian the cats are more likely to leave alone (probably neither, unfortunately), but toads will survive better than frogs in an urban garden. Toads live on land all the time, except for when they lay their eggs in a pond, lake, or stream. Frogs, however, spend nearly all of their time in the water, so unless you have permanent water on your property, frogs would not be able to live there. Now that I think about it, toads might be better able to hide from cats because they can burrow a little into the dirt and also camouflage themselves (with their brown colour). Frogs can't dig into the dirt. I don't know how to attract them except to catch some in another location and bring them in. Try to find males as well as females. The males are small and the females are much larger.