Simple observation. You will either see them fighting or see the damage on the fish that indicates they have been fighting.
Generally speaking, Betta fish will puff up and frill out their fins when acting agressively.
its not upside down
They are not hungry
When it is floating not swimming.
When the fish is swimming around by the top of the water, or where you ushually feed them.
No, fighting fish (Bettas) are only interested in fighting with other fighting fish.
Exactly as you spelled it in your question; a Betta fish is also known as a Siamese Fighting Fish.it is spelled "Betta", or its other name, "Siamese Fighting Fish." I know alot about Betta's. :D
Of course they can. How else would we have fighting fish.
I do not know. I would highly consider asking you local fish veterinarian.
The scientific name for the Japanese fighting fish is Betta splendens.
They ate fish before battles so they could keep fit and healthy and also so they wouldn't be hungry while fighting.
Yes it is very Hungry
If your fish is a fighting fish it will be still for most of the day and probably attack another fish who wanders into his "territory". Fighting fish often come in bright colours like red or blue. But some fish are just naturally aggressive and hurt or kill your other fish! {trust me I've experienced this } It's very important to know the difference between a aggressive fish and a fighting fish. If you still can't tell talk to your local pet store or talk to an expert.
When do fish eat? When do fish eat?