My first ever 3D model design, the V1.0 conure nesting box. Designed on Fusion 360, uploaded as an 3MF file for Orca Slicer, and separate STL files for all three pieces.

12x 6x2mm magnets are needed to attach the top to the body. Amazon (affiliate link)https://a.co/d/ajlECW6
You might as well use any that fits the same dimensions.
The picture I took from the bottom doesn't seem that good because I used support. I'm not sure why it told me I needed support, but it was a test model I went with and I ended up with leftovers. Anyway, my GCC loved it and slept in it every day. Keep in mind that if you open the top, their tail will stay outside. You can place double magnets to keep some space for their tail to wiggle outside if you want.

I printed this on P1S PETG using the 3MF file 'Bird Nest 2' by Bambu Lab with default settings. The file is named 'bird_nest.3mf'. I used Orca Slicer and my settings for PETG printing.