Okay, so background...
We have an 18 month old DS, our biggest challenge in the past 18 months was his colic, but once that was done with (thank heavens!) he developed a sunny and easy going personality. Lucky us. So, his behavior over the past couple of weeks has really been atypical for him (based on what we formally assumed about his personality).
From gentle kissing and pets of our dog and two cats (behavior which we have always taught and reinforced) he has started grabbing their fur, tails and trying to sit on them (all of which are totally unacceptable). So far we've handled this by removing the animals from the room (they can go into the kitchen where he can't see or get to them) and we explain that if he's rough and hurts the animals that they have to go bye bye in the other room. Tonight after he tried to grab the dog I told him "no" and held him in my lap so that the animals could be put away without him trying to chase them. He cried and struggled but I held him while explaining that he could get down when the animals were put away. And, that if he was rough he couldn't play with them.
Also, he has started hitting/biting/pulling on us. Tonight he came up behind DW (while she was sitting on the floor) and pulled her hair so hard that she fell backwards. Once again, unacceptable. He was startled and we told him "no, that hurts mommy" and then had him give her a hug (not thrilled about the idea of forced apologies-- but it felt like some sort of positive physical affection needed to happen).
Lots of whining, lots of demanding behavior in general and since he is non-verbal we spend far too much time trying to guess at what he wants. We are going to be upping the ante on signing--he can, and does, sign for more, nursing, water, all done and please (oh and siren and ball :)
We don't allow artificial coloring/flavoring--there have been no food changes lately--sugar is fairly minimal and when offered fairly hight quality (a Tbs or 2 of vanilla ice cream every couple of weeks is about it).
Any other suggestions? Is this kind of major behavioral shift typical for toddlers this age? What other tools (apart from the gentle physical restraint, used only to ensure the safety of moms and animals) would you suggest? We have Happiest Toddler on the Block and do implement some of the suggestions and we use Playful Parenting as well.
All that said--are 18 month olds just like this? And, if so, when will our mellow, happy boy come back?!