I have 1 question on 2 children!

Question: Is it just the age that:

Chelsea (29 months) is
* Refusing to eat breaky, lunch and dinner because 'My cant like that' or 'My cant eat that'
* Misbehaving (biting, pushing, pinching, back chatting, hitting and screaming)
* Refusing to listen
* Refusing bed day and night

Zachery (3 months) is
* Waking alot more (early mornings)
* Not sleeping through (as in 9pm-8am) like he used to
* Having bigger bottles
* Feeding more (some days we only just make it 3 hours..others we make it 5+ hours)
* Sleeping less through the day