That is very true! & Outside would be good, that's what I always do. I usually put it under a tree in a little dish. Very few are capable of actually taking the entire thing, though, I've put a little lollipop out there, and it was off the stick and gone in less than 24 hours.
It's more of a spiritual offering, so leave a portion about half your palm & unwrap any candy. Remember, they really hate littering. They like juice, milk and most dairy products, cakes & baked goods, pastries, icing, sugar, fresh fruit, and honey. They also like little shiny trinkets, beads, glitter, textiles, especially natural items like flowers, leaves, and pretty stones. I've heard of people leaving out alcohol and beer for them as well and they loved it! I hope you bond with them well
O & don't leave out iron, that wards them away. Once you get to know them you can invite them on nature walks and such. I usually take a box of wildflower seeds and plant em at the park for the bees