Judy, yes you will have to remove some of the nest from the box if it is a full nest. This year I have had more trouble with this than usual, but too much nest will, most of the time, prevent the trap from tripping. If I am sure the HOSP are around still, I usually will try to take out most of the nest and then set the trap again in the hopes they will be curious and wonder what is happening. But, then, sometimes I will just take out the whole nest. About a week ago I found a HOSP nest with 2 eggs in it, so I took out the eggs and part of the nest, set the trap but after two days they did not come around so I removed the whole nest.