Wings is correct, he was mimicking a burp. They Can't burp. I know for a fact when one time, I was giving my grey a drink form a glass of water that my kids left next to the cage. When she wouldn't stop drinking it, I mentioned that fact to my kids, it was like she never had a drink in her life and was dehydrated.....it was then that they told me it was sprite, that was on the flat side......I freaked out, it was the weekened, and had to call Tufts University Emergency Animal Hospital for advice as they aren't capable of burping. She eventually, threw it up several times and it got out of her stomach...