Pitfall Traps are used to collect ground dwelling insects and arthropods. A container with or without preservative is placed in a hole in the ground and the organisms while crawling fall and trapped into the container.  After the hole is dug into the soil, the collection container and funnel are placed as shown in the picture or video and are soil packed around it to the level of the lip of the inner cup. It is important that the lip of the inner cup or funnel is properly level with the surrounding soil, otherwise small organisms may see it as a barrier and go around the cup or burrow beneath it. Also, we have a different grades of litter separator that stops falling litter and other stuff into the collection container. This needs to be ordered separately; for this you need to mention the size of the metal mesh needed as a barrier filter (2, 4, 8, 12mm hole size netting is available)

The elevated metal cover is placed over the pitfall to keep out water, falling debris, and partially protect against curious mammals. The cover only needs to be ~10 cm (3 inches) above the cups. Covers can be made of almost any material and if the pitfall is not meant to be left out for very long a disposable plastic plate held up with kabob skewers will work.