My 18 month old boy's behaviour has suddenly changed. He hits out sometimes at other kids. Throws soil/sand into the house or at people! I think this is quite normal behaviour but everyone around me keeps saying i must punish him and tell him off for all these things. I do always say no in a strong voice but all he does is laugh and giggle at me and normally goes back to what he was doing. Everyone is doing my head in about it. I dont think he quite understands when i tell him off he thinks i am playing along with the game. I think he is still a bit too young to udnerstand me telling him off. but everyone around me says you must tell him off and make him cry and udnerstand but however much i say no (i even tried shouting it)he still laughs he is not scared of anything. He is a very tough boy, he always falls over and never cries! I think more towards the age of two they would understand and then maybe do the naughty step. But has anyone got any ideas for now? sorry for going on a bit!