A reader e-mailed in this question:
“I think I have termites on my roof and near my chimney but my landlord says this is impossible because they can’t live outside and die from sunlight. I can’t find anything about this. Help me!”
Yes, this is at least partially true.
Worker termites die when exposed to sunlight or the open air because they need the moisture of their colony.
This is the reason why they build little mud tunnels – so that they can travel from wood to wood without being exposed and dying.
However, that doesn’t mean you couldn’t have a colony on your roof. It just means the workers would have to stay inside the wood. There are also some termites that can live outside the colony and in the sun, specifically the swarming reproductives that fly around to found a new colony. If you see them wandering around outside on the roof, though, your landlord is probably right. But that doesn’t mean you’re out of the woods – it means you probably have carpenter ants instead, a pest that also be damaging. Carpenter ants look a lot like termites, but they do not use the mud tunnels and they often establish colonies that are above and outside the wood as well. They usually don’t cause as much damage as termites, but if you get a large enough colony going it can still undermine the structure of your home. Carpenter ants require different treatment from termites, and often the exterminator will focus on eliminating the nests specifically rather than treating the home in general.