tail light

Hi all,
Not sure if this is the right place for this question.
I have a 1996 sportsman 400. Bought it about two months ago, its my first ATV.
I replaced both front head lamps and the tail light bulb. With the key on, both head lamps come on only with the switch on low beam, both lamps go off when switched to high beam. I assume this is normal due to the bulbs i put in. Not an issue, its plenty bright.
Used an 1157 bulb for the tail light. Tail light comes on when the key is turned on and brake light comes on when i hit the brakes. Tail light is always on when the key is turned on, even with the light switch in the off position. Is it supposed to be that way? Maybe some kind of a safety feature or do i have a faulty on/off light switch? Will it hurt anything to leave it this way? Also i replaced the battery at the same time.
Thanks