My recently found a young budgie outside at our neighbourhood a day ago. We're assuming its been taken care of by someone else before because it went to my dad when he reached his hands out. As we had no cages to house it in and neither could we get one because it was already late at night, we placed it in a cardboard box with some water and food, and covered it with another piece of cardboard with a slight gap to allow air flow. The next morning it was trying to get out, flying against the cover to try and escape. We had to put it back in a couple of times before we let it out to do its own thing. It was active and it flew around a lot, exploring the house. When we got the cage, however, it ate a lot and started sleeping a lot. We assumed it was probably tired and shocked from being out in the wild for who knows how long, and what it experienced in our house before we got the cage. As I'm writing this it's been more than 24 hours since it started sleeping. It wakes up occasionally to preen its feathers and to eat and drink a little before going back to sleep. So far we've fed it some millets. It also tends to prefer sleeping at the bottom of the cage, and it has droppings stuck to its bottom. Its droppings are white, sometimes with dark green parts (when they are not stuck to its bottom). I'm very worried and I'm not sure what to do. I have plans to bring it a vet as soon as I make arrangements.