It's natural.
I remember my sister having a difficult time with her two sons. They were very young - the elder was 2, the younger was 18 months (adopted). The elder was a hair-puller, the younger was a biter. She had tried everything to cure the younger one of biting, even biting him back (not recommended these days although I know people who have done it and this was back in the early 70s when people did this sort of thing sometimes).
One afternoon she had stopped in our driveway beifely, to see our mother. She turned the car off but left the doors open, both boys in their child seats (what passed for child seats in those days). These seats had no harnesses, but had a padded bar across the front plus a vertical leather strap that went between the horizontal bar and the seat, so the boys had a leg either side of the strap. Very much like a high chair seat. So they did have more freedom of movement than in modern child seats.
We had just gone inside when we heard screaming. Both of them. We rushed outside to see drifts of white-blonde hair flying around the car (from the younger boy). My sister hauled off the elder and spanked him for hair-pulling but our mother said, "Hey, he was screaming too, before you caught him in the act."
Se we looked - and elder boy had a very large and rapidly bruising bite mark on his arm.
We mentally recreated the events - as soon as Mum was out of sight, baby brother (who always was a devil) leaned over and bit the elder brother, hard. Elder brother instinctively reached down to pull the head away from his arm, grabbing by the hair and pulling, hard. Both boys hurt, both boys screaming.
And from that day, younger never bit and elder never pulled hair.
Instant cure.
But I don't recommend it.
Marg