So, my friend came up with this, and I love it! Remember that story of the kid who got stuck in the pizzeria after dark? Maybe he was stuffed into the BB suit. He says "Hello?" Like he's asking if anyone's there. The kid couldn't find anyone, so he probably said the same thing. BB says "Hi!" when he sees you or another animatronic, so possibly when he found an animatronic that night he said hi to it. The story says that the animatronics put on a show for him, so maybe that's why BB laughs. Because he was entertained by the animatronics. Since BB attracts Foxy, maybe Foxy was his favorite or he was the first animatronic that saw and helped him. This theory is probably why the mother didn't find her kid the morning of the incident. Tell me what you think!