Trap-Door Spiders and Tarantulas. In the country where trap-door spiders occur they may be located by walking slowly up on the slopes and shoulders of the brushy foothills. One must develop an “eye” to see the faint ring denoting the outline of the door. The door can usually be opened by inserting a needle or pocketknife blade opposite the hinge. Occasionally a green oat straw or other thin reed may be inserted down the length of the spider tube and then be carefully withdrawn with the spider in pursuit. Usually, however, the spider must be dug from the ground, tube and all. If most of the dirt is cut from around the tube, as the excavation is made, most of the tube can be placed in a tall, wide-mouth museum jar. Additional soil may be tamped in around the tube to hold it in position and the spider placed inside.