odly enough, you can actually buy chicken/bird traps.
http://www.wildlifecontrolsupplies....01&Product_Code=WCSRC24&Category_Code=NWSBT00
It's like a snap trap that encases them in a net instead of hurting them. Since you are having a hard time locating her roost spot, it sounds like you need another solution.
Is your hen bonded to your other birds? Even if she isn't, this may still work. Chickens are social, and want company. When our guinea got away from us, she was lost for two weeks before people in the next neighborhood over came knocking on our doors saying she has been living in their front yard (to this day, we still have no clue how they knew she belonged to us!).
After two weeks, she was EXTREMELY skittish. With the cooperation of the neighborhood, This is how we caught her. Her favorite treats in a dish (live mealworms)? Check. One medium sized dog crate with the divider? Check. Blankets? Check. Her best buddy in the whole wide world? Check. We placed her buddy in the back half of the dog crate, and set up the divider to keep him in. We placed the dish of mealworms on the other end, with the front crate door opened. Covered one side of the crate with a blanket (the side where the door hinge was), to block her view of us walking up to the crate.
We walked out of the yard, and watched and waited, and let her mate do the work. She saw him, he saw her. Her whole demeanor changed. They began calling to eachother, and slowly, she started coming towards the crate. The instant she realized that her companion AND food (her whole world) were in that crate, she was determined to get in there....now, guineas are not the brightest, so it took her a minute to figure it out, but she finally walked in. I slowly crept up on the blind side of the crate, and quietly shut the door.
We covered the entire crate with the blanket (to keep her calm), walked it out to the car and drove the whole crew home. We shut her in the coop for two weeks, just to make certain she knew where to go, and to treat her...she had a bad limp, and we wanted to get her back up to a healthy weight. Since then, those two were insepearable, and Snow Pea never wandered again. Good luck catching her...
