Yes, most Quakers behave this way - in the wild, Quakers build very intricate nests. They protect this nest, and it appears to be an inbreed characteristic. By teaching your pet to step up onto a stick or bird perch, you can easily take them out of their cage. I started this training by having mine "step up" from one finger to the other. This is completed by gently pushing your finger into their chest while saying, "step up." When they begin to do this automatically when you say this command, then start training with a stick. It will be easy to get them out of the cage using the stick to get them out - once they are out of their cage, you will have a sweet bird again.