Ninja composting , the perfect accompaniment to Guerilla gardening!
Seriously though, finding rats in my yard, neighborhood of half-acre lot suburbia, has given me pause. They are living in or under the neighbor's shed. He knows it and has removed his bird feeder but no other direct action. My cat apparently has killed at least three and brought them home.
I had been throwing kitchen waste on my open piles of dry leaves over winter. And spilled bird seed from a feeder not too far from that..
I guess rats could be seen as simply extra-jumbo voles, but I'm skeeved more at rats. and we also have a BIG problem with 'deer' ticks which actually live on rodents, so for me rodent control has gone much higher on the priority list.
None of this is to accuse anyone of fostering rodents or any other problems. I guess my point is, just be aware those other problems might creep up at times, with ANY system.