>But, they keep building comb in the feeder box? I am confused.
Any space bigger then 3/8" will be filled with comb. What are you confused about?
> I am scraping the comb of whenever I see it.
And they will simply build it again as long as they have access to space bigger than 3/8".
> Is there something I can do to stop this.
Limit the access. If we are talking about a frame feeder, they probably jsut want a ladder.
You can rework it to look like this:http://www.beeequipment.com/products.asp?pcode=710
It has limited access and a screen ladder going down into the feeder.
Or if it's a miller you can rework it with a screen that only gives the bees access to the syrup.