Wildlife sanctuary on a rooftop

As I expand the number of plant varieties on our rooftop, currently about 50, the variety of wildlife seems to increase alongside to it. Not only do we have our very own bumble bee who helps me pollinate the zucchini (courgette) flowers, but we also get frequented by the most beautiful dragonflies and butterflies. Our garden sports an impressive collection of spiders who do a marvellous job of keeping the mosquitos at bay. An army of lady bugs works relentlessly on their campaign against aphids and other such unwanted intruders. The compost bin is the megapolitan place of residence of numerous insects and micro organisms. And the cats? Well they have the easy job, I guess. Except for the occassional hissing to scare off other neighbourgood cats and birds, they live the good life, luxuriously bathing themselves in the sunlight.