Deletion of Heat Mat (Vivarium)

Comment: because the article is too short and not particularly notable enough to stand alone; the material works better in Vivarium.  I don't think this is a  case though, because although the article is a stub now one could imagine it being filled out with the history of heat mats, heat mat controversy, etc. etc.  It's as much a potentially encyclopedic topic as Aquarium, I should think
Stance: merge
Cited policy: Wikipedia:Wikipedia is not a dictionary (WP:DICTDEF)