Some balls will fast once they are breeding age, usually seasonally. My normal male was most likely a wild caught import. I bought him from his original owner when he was about 2 years old in 1992. He was more rescue than purchase (covered in another post), but he has gone off feed for up to 6 months at a stretch. It isn’t every year, and as long as he didn’t drop body mass I wasn’t overly concerned. In the last few years, he hasn’t gone off feed for those long stretches, and I always offer anyway.