A system (1,41) for determining a likelihood that a human or animal is present based on sensing input, said sensing input reflecting changes in radio frequency signals received by one or more devices (16,31-36), comprising: a receiver (3,43); a transmitter (4,44); and at least one processor (5,45) configured to: - use said receiver (3,43) to determine said sensing input, - determine said likelihood that said human or animal is present based on said sensing input, - use said transmitter (4,44) to control a lighting device, in a normal operations mode of said lighting device, to render a light effect upon determining that said determined likelihood exceeds a presence detection threshold, and to continue to render said light effect for a subsequent predetermined period of time even when said determined likelihood changes by more than a predetermined value within said predetermined period, characterized in that said at least one processor (5,45) further configured to: - use said transmitter (4,44) to indicate, in a configuration mode of said lighting device, said determined likelihood to a user via said lighting device by rendering a further light effect of a plurality of light effects, said further light effect being selected based on said determined likelihood, wherein said processor is configured to determine a value of a plurality of values corresponding to said determined likelihood, with each value of said plurality of values being associated with a respective likelihood range and with a corresponding further light effect, wherein said processor being configured to select a subsequent further light effect, of said plurality of light effects, different from the previously selected further light effect, upon determining that a subsequently determined likelihood corresponds to a different value as compared to the previously determined value. a receiver (3,43); a transmitter (4,44); and at least one processor (5,45) configured to: - use said receiver (3,43) to determine said sensing input, - determine said likelihood that said human or animal is present based on said sensing input, - use said transmitter (4,44) to control a lighting device, in a normal operations mode of said lighting device, to render a light effect upon determining that said determined likelihood exceeds a presence detection threshold, and to continue to render said light effect for a subsequent predetermined period of time even when said determined likelihood changes by more than a predetermined value within said predetermined period, characterized in that said at least one processor (5,45) further configured to: - use said transmitter (4,44) to indicate, in a configuration mode of said lighting device, said determined likelihood to a user via said lighting device by rendering a further light effect of a plurality of light effects, said further light effect being selected based on said determined likelihood, - use said receiver (3,43) to determine said sensing input, - determine said likelihood that said human or animal is present based on said sensing input, - use said transmitter (4,44) to control a lighting device, in a normal operations mode of said lighting device, to render a light effect upon determining that said determined likelihood exceeds a presence detection threshold, and to continue to render said light effect for a subsequent predetermined period of time even when said determined likelihood changes by more than a predetermined value within said predetermined period, characterized in that said at least one processor (5,45) further configured to: - use said transmitter (4,44) to indicate, in a configuration mode of said lighting device, said determined likelihood to a user via said lighting device by rendering a further light effect of a plurality of light effects, said further light effect being selected based on said determined likelihood, wherein said processor is configured to determine a value of a plurality of values corresponding to said determined likelihood, with each value of said plurality of values being associated with a respective likelihood range and with a corresponding further light effect, wherein said processor being configured to select a subsequent further light effect, of said plurality of light effects, different from the previously selected further light effect, upon determining that a subsequently determined likelihood corresponds to a different value as compared to the previously determined value.