This is a box that looks like a bird house / nest box , so very discreet . aHouse sparrows kill other good birds to expand and take over more nesting boxes . This trap does not kill , it only traps , then you can look inside and determine what has triggered the trap . There is a You Tube video on how this box works . so you can build your own , or just buy one . email protectswallows@shaw.ca cannot leave my cell number as i get too many scams from this site.