Is it normal? My 18 month old is showing weird behaviors like taking cloths off, biteing buttons off remotes cloths, biteing self and others, saying words like why over & over, loud scream out burst like aah aah, throwing things when mad or upset.tip toe walking, spining or walking in a circle. I ask here if she wants something and she repeats what I say but knows how to say yes and no. Should I be concered or not?