Twin speaker unit maximizes db output and coverage area to deter cats dogs and foxes protect your garden habitat with the big cheese cat repeller it can take between 14 28 days to deliver full protection or 7 days on occasional visits there are 9 million cats in the uk the mammal society says cats kill around 275 million prey items a year including 55 million birds voles and other small mammals make up much of the remainder the sonic cat repeller will help protect your garden habitat and encoura