I don't know... perhaps it's a sense of insecurity and fear? The only toddler dream I remember was seeing three skeletons in a balloon floating across a field of snow soaked in blood. I ran into my Mum and Dad's bedroom crying that the Father Son and Holy Ghost were going to kill us. Apparently I was threeish or fourish. Benefits of a Catholic upbringing.

Perhaps there's a familial or cultural element to your dreams? Did you have a relative die a violent death (accident or otherwise) when you were young?