It's Halloween. A lot of creatures will visit your door. Be open minded. The child who is grabbing more than one piece of candy might have poor fine motor skills.
The child who takes forever to pick out one piece of candy might have motor planning issues.
The child who does not say "trick or treat" or "thank you" might be shy or non-verbal.
The child who looks disappointed when he sees your bowl might have an allergy.
The child who isn't wearing a costume at all might have a sensory processing disorder or autism.
Be nice. Be patient. It's everyone's Halloween.