Trick-or-treating isn't for babies
Consider this my unpopular parenting opinion. Babies should not go trick-or-treating. When you have an infant, trick-or-treating is more for the parent than for the child. I'd rather stay at home and watch PG scary movies than stomp around the neighborhood with a baby in costume.
I promise you that I am not the Grinch of all fun-filled family holidays. In fact, I have a special love for Halloween because I was not allowed to celebrate for many years growing up in a religious family — unless you count the knockoff Harvest Festival that encouraged biblical costumes, which I don't.
I love Halloween. I love my kids. I just think we all know what's going on when a baby shows up at your doorstep begging for treats on Halloween. If you look a little closer, you might notice that there is a tall adult holding the baby at eye level. You see, babies can't walk door-to-door to trick-or-treat, they can't ask for candy, and they also can't eat any of the delicious candy that you drop into the pillowcase the parent is holding.
When you give candy to a baby on Halloween, you are giving candy to his parent. You are an enabler, and you've also fallen for the oldest trick in the book. (Perhaps that's why they call it trick or treat?)
There are some people who have a great disdain for teenagers who show up on their doorstep and demand candy on Halloween. This group believes that teens are far too old to trick-or-treat, and I see their point. On the other side of the argument, babies in costume shouldn't be allowed to trick-or-treat either. They are far too young, and everyone knows hard candy is a choking hazard.
Babies are certainly a special part of Halloween, when used strategically as the prop they were designed to be. As any new parent can tell you, babies are essentially inanimate objects for a good six months. If you time everything right, between a feeding and bedtime, they will happily sit in a festive fall wagon on your doorstep so that everyone can ooh and aah as you hand out candy to actual children dressed to trick-or-treat.
Dress your baby in costume on Halloween. Take pictures of him and post it to social media. Take your costumed baby to a relative's Halloween party and pass him around. Just don't use your baby as a poor excuse to score candy because everyone will see right through you. Babies can't trick-or-treat.