Discussions

I guess conditions are right for what they call "swarming nuptials ". They are getting ready to start new colonies.  
 
I didn't look, but if they have heart shaped heads, they are carpenter ants.  
 
https://www.canada.ca/en/health-canada/services/pest-control-tips/carpenter-ants.html  
 
https://www.orkincanada.ca/blog/ants-with-wings/

We also have them in our yard. They are everywhere.

Weather is a big factor. Certain weather conditions are super great for their expansion.  
and they spread fast from one area to next.  
 
Get them under control and killed before they infest anymore.  
 
They can cause a lot of damage (various larger ants - some with wings) to your plants, your house or actually anything around.  
 
And when they get into your house and crawling yuk!  
 
Look for homes in trees especially stumps; and if you have a wood pile. They love them.  
 
As the city is cutting every tree in sight this may be stirring them up as their home is destroyed.

Is there any way to kill them that is safe for pets?  
 
I don't imagine you want to start moving infested wood until the ants have been treated?  
 
They would probably just spread out searching for other areas to nest?

Yes, it is not just within the cities. There is a lot of dead trees everywhere due to the various weather & bug infestations of the last bunch of years. Add to this that the weather is now ripe for expansion, and you get this new problem.

We got them too, They were horrible for a day and have left but.... Im on the hunt for something that does work. I have a pesticide license but also pets that I love dearly. Everything I found but Torros is really harm full. You can find it at Canadian Tire and Home Depot but its not very strong.

Mix vinegar and water together and spray on the ants.  
 
Other items like caulk and hot pepper helps to keep them out of your house. Search on the internet for other ideas.  
 
Plus in the house dispose of all dead ones as with anything the dead ones seem to attract the live ones.  
 
I also use ant traps in the house as if you put them in areas that your pets don't get at them.  
 
Don't have to move your wood pile. Just keep treating it especially in hot weather as that gets them more active.

Finally managed to track one down right in my own driveway.... Kiddo knew I'd been on the hunt and was actually the first one to spot it. No hill found but on a day like yesterday I’ll live in blissful ignorance that it came in with the wind (measurement units are cm)