Found a few of these, what I believe to be Lasius niger queens. The wingless ones were probably a little under a cm in length, some of the winged ones were smaller which I presume were males. Honestly, if I hadn't been at my day job at the time, I'd probably have tried to take one or two home with me.
#1 rule if you want to catch an ant: Always carry a small glass bottle or a plastic test tube around with you - you always find them when you're not actively looking for them.
But NEVER carry caught queens directly at your body - the excess heat from your skin can kill them quickly. Instead put them into your jacket pocket, bag or backpack.
Yes, it looks like Lasius niger (might also be Lasius flavus if it has a more yellowish lower side, they're pretty much the same except L. flavus gets yellow workers).
I'm sure you will have another chance to catch them, they usually fly 2-3 days in a row multiple times throughout the summer.
Lasius niger is btw a brilliant beginner species that thrives in pretty much every environment and is very forgiving even if you make mistakes in their keeping (same goes for Formica fusca). You just need to place the queen into a test tube setup with cotton and water and leave her alone for 3-4 weeks. She doesn't need any food and the water from the test tube is sufficient. When she has first workers place the test tube setup in a small plastic or glass container (don't forget to apply a barrier to the container top sides like baby powder or Fluon), put a straw through the cotton and offer a tiny drop of sugar water or honey and a fruit fly or a small spider.
I caught a Lasius niger queen about 20 days ago (they were everywhere) and she already has larvae =)
Actually keeping termites is becoming a thing as well.
They may not be directly related (ants are descendants of wasps while termites are descendants of roaches) but they are also quite interesting to watch and keep (note that unlike with ants you need a queen AND a male to make them breed).
If you're keeping the right species (like dampwood termites or a species that eats moist leaf litter and wet cardboard) there is basically zero risk that they damage your house should they escape. Like with ants there are different species for different petkeepers, some can grow really large colonies but a lot of them also stay relatively small or grow very slowly.
The Formiculture antkeeping forum even has a termite section now:
Stupid me just removed the pink cover foil I accidentally left on the glass all the time : now you can see the ants in all their natural beauty:
They also got a second nest attached but have successfully ignored it for over half an hour. Well, one worker walked like 2cm into it and they have set up a few majors at the port (inside the old nest), so that's something I guess...
Also, to give you an impression of how huge and massive these ants are (almost 2cm), here's a size comparison of a supermajor and a beach tiger beetle that should be about right:
If they are in a test tube I wouldn't heat them at all. Test tubes are prone to overheating (the heat accumulates inside the tube much more than you might think it does), also heating often causes condensation which in test tubes can lead to flooding.
If they are in a nest you can use a low power heat mat and put it below about a third of the nest (definitely not more than half), preferrably either at the opposite edge of your hydration chamber (so you have a synchronized temperature and hydration gradient which should result in little condensation) or in a way that it also covers half/a third of your hydration chamber side (then you get a temperate gradient in a 90° angle to your hydration gradient which means the ants have maximum choice with 4 different environments - warm+wet, cold+wet, warm+dry, cold+dry).
Depending on how the ants react you can further optimize your setup (if they're all on the warm part you can cover a bit more of the nest with the heat mat, like 3/4, if they're all at the moist part close to your hydration chamber you need to water the nest more frequently, etc.).
If your nest has a port for a heating cable (like the AC hybrids or the simants nests) you can also mount one in there (a 15W cable should be enough).
Um... sort of (not really though). The thing is adult ants need very little protein so if they don't have brood they will probably just lick off any wet stuff and then ignore the meat as it dries out.
Also remember that meat starts to smell very bad very quickly (unless it's like ham or dries out).