My garden is in a built up area of Birmingham with many houses owning cats, who are more often out side roaming than they inside. They pay a lot of attention to the chickens and come pretty close up. My girls are part free range. (When I'm work there in the run) but on my days off and weekends there in the main garden free to roam. Most of the time I'm in The garden or house watching out of the window, and checking up on them. How worried should I be about the neighbourhood cats?