Otherwise calm 3 year old biting
My otherwise calm almosy 3 yr old has started biting. Always in the evening when he is tired.
First time: tried to bite at gym daycare.
Second time: 5 year old sister when he wanted her toy.
3rd time: at a restaurant where kids were playing near an arcade.
He does not otherwise have behavior issues. No tantrums or hitting. It's minor annoyance strait to biting. His talking is not super clear to others, but he can clearly tell us what he wants and communicates well. He is not in daycare and has a nanny. Has not bitten anyone with her.
Each time we give clear consequences and a calm by firm reaction.
We can avoid the situations that have caused it and reinforce the rules. Reminding him about getting something he wants after a good gym daycare session has worked so far to avoid another biting there.
Is there something specific we should be doing?