So two lazy people making fun of a special needs person. Lovely example

I'm going to assume that this may be a weekday and they may work from home; unable to take a break to help shovel. OPs roommate may be the one who's mentally challenged if something like that bothers him, and OP has the right to say 'As long as they don't shovel it into my yard' (I'm also going to assume here OP meant his driveway, especially if they're side by side) whether they're challenged or not. No one likes to shovel again if they don't have to! I'm just throwing possibilities out there. The neighbor may do it to pass the time. My hometown there's a couple mentally able but challenged people who do these things multiple times a day to keep their minds and bodies busy outside. Nothing wrong with them doing it routinely alone. :)