betta fish...do they need lights in their tanks?

Bettas need light, but they usually get enough without a tank light. DO NOT leave your betta in direct sunlight, do not leave him in front of a sunny window or anywhere that gets a lot warmer when the sun is out. That will seriously stress him out. Just put him in a room that is well lit most of the time. If your house is really dark, or you leave him in a dark room for part of the day, you should get a light. Just remember to turn it off at night so he can sleep.

Hopefully the tank is at least 2 gallons. Bettas prefer warmer temperatures, so if you don't have a heater, a light might be a good idea to at least warm up the surface of the water. Otherwise, as long as there is ample natural light, he should be ok.

some light source. what size tank is it? will it support a tank light? most small tanks have lids that fit and have lights. even my 2.5 have full hoods and lights. bettas should have lids on their homes because they are jumpers, but they still need to be able to breath the surface air,o it can not be so tight fitting this can not be done.

The fish will probably look better with a light on it, but the fish itself doesn't care much, as long as there is a reasonable amount of light in your room.