They think intuitively .. Instinctually. They certainly have fears that spring from that.
How do babies think as they have no language, or are they spared from the bombardment of thoughts regarding past and future fears?
You ask good questions; you have a good mind.
Here's a link that will give you some concepts that can form a basis for your thoughts on the issue:
http://mentalfloss.com/article/50684/it-possible-think-without-language
Who ever said babys think? Thinking is a learned behavior and babys learn mostly by watching their surroundings and after a while most becomes etched into their brain but Parents teach their kids to think and schools contribute to this over the years. Babys learn fears by trial and error and again by watching others around them, mostly siblings , if applicable. And as seen just because we are born with a brain, doesn't mean we know how to use it and some people never learn at all
I remember being born.