Stronger and happier every day.

There’s a good reason babies (anywhere between 4-6 months) constantly put things in their mouth — because their mouth has more nerve endings than any other part of their body — hence the constant need to suck on something.
But in general, 5 months old babies tend to be happy babies. Sometimes they might even laugh at your attempts to play with them, hold your hand with their chubby little fingers and cuddle you when sleeping.
You may also find that your baby is (thankfully) not waking up in the middle of the night. The best way to establish this to ensure that you have a good bedtime routine set up that is followed each night.
Babies with active muscle movement might even enjoy being put in a sitting position. For them, it’s a whole new angle to look at the world.