barbie clifton, a mother of five, was attacked at an ohio chuck e. cheese during her daughter's birthday party. >> all i really remember is hitting the floor. and my hair being ripped and ripped. and kicked in the head. the lady was infuriated over my children being on the picture machine so long. >> reporter: susquehanna, pennsylvania, they were all-too frequent visitors to chuck e. cheese. >> we had an 18-month period when we were there 17 times. >> reporter: chuck e. cheese wouldn't give us an interview. but they sent us an statement. in 2011, 99.99% of 65 million guests occurred without incidents. despite our efforts, altercations occur with a very small percentage who visit. typically the incidents are not with the kids. but regrettably, with the parents. >> what you really see here is chaos. >> reporter: we asked two psychologists to watch these fights. doou find this behavior surprising? >> not really. birthday parties are really emotional situations. >> reporter: heightened emotions, happy or sad, can quickly turn to anger. and people bring u