DALLAS - Visitors to the Houston Zoo can now pack a little something extra besides a camera.

The nearly century-old institution recently lifted its longtime firearms ban amid a broader push by gun-rights advocates who are pressuring zoos in Texas and elsewhere around the U.S. to do the same.

Gun-rights supporters say publicly owned zoos have misinterpreted laws and are illegally banning firearms.

Some zoos have countered calls for policy changes by claiming they are considered amusement parks, day cares or educational institutions - all venues that legally can enforce gun bans in many states.

An advocacy group in Texas is singling out zoos under a newly enacted state law allowing gun-restriction complaints to be forwarded to the state's attorney general.

Starting Jan. 1, licensed Texas gun owners can openly carry firearms.