In addition to the angelfish tanks, I have two beautiful bettas. They each have their own two gallon tank on the counter between the kitchen and the breakfast room. It gives them plenty of opportunity to watch all that goes on.
The other is a golden double veiltail. He is about two years old. He lives with a snail, who helps to keep his tank clean. Sometimes bettas will tolerate or even enjoy a snail in their tank because it gives them someone to watch. Other times, they try to get aggressive. That's why the peacock betta does not have a snail living with him.
I've heard people say that they put bettas in community tanks. But you have to be careful when doing this, because their long, flowing fins slow them down considerably - making them easy prey for fish who like to nibble on those fins, like barbs and some tetras.
If they are placed in a tank with other fish with flowing fins who look similar to them (such as male guppies) they will often mistake them for another male betta and fight.
Bettas also need shallow water and they tend to live near the top of their tanks, because in addition to breathing through their gills they can breathe air from the surface. So the tall tanks I have for my large angelfish are inappropriate for the bettas.
They are carnivores, which means they only eat plants when they are starving to death. That means those vases with a plant stuck in them that are marketed to people wanting a single betta they never have to feed is simply cruel. It also gives people a very wrong impression about the care bettas need to thrive.
When male bettas are happy, they will build a bubble nest at the surface of their tanks. They are trying to entice a female betta to come on over and lay her eggs.