Nare, I've ripped through a countless amount of logs, lifted hundreds of stones in forests, looked during optimal nuptial flight conditions. And haven't found a worker once.
I may have found a male/ queen once while tipping a nut looking for Temnothorax. It fell on my hand and I threw it so fast that I have no clue if it was a termite or an earwig.
I've found that they're super choosy about where they nest. I explain more in depth in my journal, second post I think, but they prefer wood that's not super rotted. Hardwood, I find, that you may be able to peel the bark off of, but that you cannot easily pull apart. When you flip it over, the ground underneath should be moist. I've found that logs like this often have one side that is depressed, sunken in, where the termites have dug through it. Sometimes, that part has been scooped out, and the log may be "U" shaped instead of "o" shaped. You should be able to scrape the soft wood out with a screwdriver, and dab up the termites with a wet paintbrush.
Termites are very good at hiding. As soon as you break open a log, they will be running for shelter. They can hide right in the middle of even a piece of wood half the size of your palm, and you'd never know. But you'll know that there are termites, as you'll see a couple when you flip the log.
EDIT: I don't know if you still live near the big city, but this may be of assistance. It's not set in stone - there are no reports on this site of termites in Toronto, and yet I've found them and am keeping them. https://www.inatural...taxon_id=119931
Edited by Nare, August 26 2018 - 5:22 PM.