How do I know if I need to buy a walker already for my baby? He is now 6 months old.

you can easily avoid buying a walker. i did it for my first baby but didn't use one for the second one and it was absolutely fine. by around this age, your baby will start to take support and try and get up and move. let your baby do it naturally, as it will also improve your baby's grip on the floor and the ability to walk.