"Sure. They never need to have their batteries recharged.

"
And besides that, I think they might be biodegradable. I'm surprised the more environmentally conscious among us, haven't come out with a ban on ball point pens since they are plastic and they seem to be having babies, at least in my household. I can never find a pencil, but there are armies of pens in my house probably because of the fondness of businesses finding a cheap way to advertise on them. Usually, if not used fairly regularly, they dry up and have to be thrown away so end up in the trash and eventually in the land fill along with tons of other plastic.