The false earth fitted with a Kozard Trap must have only one tunnel and entrance, so all visitors moving through it may be caught. The Kozard Trap has to be fitted approximately one meter in front of the end chamber of the earth. Tunnels may be made of bricks, concrete or PVC pipes as well. The ideal diameter is 20-25 centimetres and the length is 6-10 metres. The floor of the tunnel must be covered with sand. In PVC pipes the sand may be fixed by using frost resistant tile cement. The end chamber may be made from a barrel with at least 50 centimetre diameter, filled with earth and send to the level of the connecting tunnel.

In principle the false earths should be built at hidden, quiet and sunny locations, usually in shelterbelts, or forest patches on dry ground, with their entrances facing South or South-East. In wetlands it is more efficient to position the false earth on higher ground by building banks. Foxes in wintertime are often reluctant to dig new burrows, but they readily occupy the existing and vacant earths. In order to give a natural look to the entrance, it needs to be camouflaged with rocks or tree stumps and plenty of sand in front of it.   To guarantee that no human scent is left on the trap by the start of the trapping season, the false earths must be built during the summer or early autumn at latest.