Ds was a pretty consistent biter from about 9 months until he was about 34 months. So, yes it is a phase, just a very long one with some children. Most children STOP biting around the same age (many by 3, most by 4) --it's the point at which they START biting that varies and make some parents feel like it is a phase that will never, ever, ever, ever, ever, ever, END.
Usually it starts out with teething and just does not stop. I must admit, we actually made a game out of it when he started in with the baby-bites around 9 months. He would bite our finger, we feigned injury and fell down proclaiming he was "SO strong!" and then he chuckled and grinned in mad delight and bit us again. At first it was cute. Then, not so much. Yeah, we did not think that one through
Honestly, the main way to stop it was that right before he did it he got 'the look'. Kind of an impish little glint in his eye that said "ah hah!". Ds bit for ANY reason and NO reason. He did it just because I was there, or he was bored, or he was cranky, or he was overly stimulated and happy. Combined with hitting and throwing, he just reacted to strong happy, sad, or antsy feelings in that way. If you can catch them before they actually do it, and provide something else to bite, or hit, a lot of the damage can be averted.
The main thing that cured ds was the emotional maturity he gained close to 3 years old, combined with huge strides in his verbal communication skills. His memory, comprehension, and verbal expression all began to mature at about 33-35 months.
I will confess we also did some time in/time outs that upset him a great deal but were effective in helping him comprehend the increasingly serious attitude I felt towards his biting/hiting as he approached three years old. In our version of the time out, one parent sat with him while the parent he bit left the room. Ds was not allowed to follow, but had to remain with the unbitten parent until he calmed down enough to show he was listening to the message "We do not hit or bite mommy/daddy" and could repeat it. He objected to this in the strongest possible terms, with much crying and kicking and throwing himself on the floor, but after just two experiences of seeing that he had to stay in the room with the parent until he calmed down and listened, he began to visibly stop himself when he got 'the glint' in his eye, and would accept redirection, or actively seek a distraction for himself, and the biting stopped within about a week.
So, I think there was a little element in there where it had just become a habit, and once he was convinced we were serious, he dropped it. But I don't think that would have necessarily worked as young as 22 months, or at least, I don't think it would have worked so quickly, and with some children, might not have worked at all.
