Bunny lines are mainly caused by excessive movement of the nasalis muscle, an inverted horse-shoe shaped muscle at the top of the nose. Ironically these lines and horizontal lines just above them can be caused by Botox, and are sometimes called Botox lines.
They are rather simple to treat, in experienced hands. This treatment is inexpensive, only requiring 6-9 units, costing roughly $50-100.
I say in experienced hands because there is a slim muscle running along the bottom of this region which attaches to the lips. Tampering with this muscle can lead to a crooked smile. Also there are some decently sized blood vessels coursing lower than the target area and if these are hit there can be some fairly nasty bruising and swellling.
In some people this nasalis muscle is a little stronger than it appears and you might have to have a few more units injected.
