By the way, I noticed this yesterday. When placing candies in the floor, it can attract some ants. You can also use them to craft some spooky furniture too!
You can also get candies from crafters. If you already have the recipe they are crafting they will not give you an extra DIY card, instead, you have a chance at getting either 5 pumpkins or 1 candy from them. You can also travel to many different islands on the same day and buy 1 candy from those islands.