Our Dennis is only a danger to carpet slippers, but it is a well made point. I would just qualify it.

We have created with our gardens, parks and urban waste a fine substitute to the natural envirionments we have destroyed. Along with this we have destroyed many of the natural predators of those envirionments.

Having created the fine substitute habitats, we appear to have also introduced some predators to it. As it is the case in the wild, it is the weak individuals in this new habitat that will first fall prey to the predators. So a form of balance is being played out.

Not that this fact makes it any more pleasant for us, failing to rescue these casualties and having to watch our well-fed mogies toying with their prizes.