Mine grew pretty quick at first hitting about 3 inches within a year after I got them. Then they slowly grew about an inch the following year. When they hit 4 inches they stopped growing. The size they will grow to will also vary if you have males or females. The females can get a lot bigger. I have heard and I am not sure since my Whites are both girls but I was told that only adult fully grown females should eat pinkies. Males will be too small to consume them and can cause impaction. Somebody correct me if I am wrong, like I said it was what I have heard.