The botXXXXX XXXXXne here is that your baby is normal. Some children, often the creative and highly intelligent ones, tend to show significant anxiety responses to things like bugs and snakes and noises etc. The reason for this is how the young child's mind works.
To an adult these scary things, bugs and snakes and so on are processed much more in the brain's logic center than in the part Zander is accessing called the Amygdala. Adult reaction, even if fearful, tends to be somewhat logical. And, we know as adults that bugs and snakes do not suddenly arrive in beds, basements and so forth because our brains prepare us for where they should/might be. Sounds also are not treated in a reactive manner but in a more logical one.
Your son is so young that his brain cannot yet distinguish between what is real and imagination. And, some reactions to things such as to bugs and snakes and loud noises are instinctual to being human child. Some of us just have the reaction a bit more pronounced than others, but it is still normal. As a matter of fact, between 18-2.5 years of age, fears of this type are very common.
What to do? First off, I think you can relax. Although a bit more reactive than some children, Zander is well within normal behavior patterns. Fear response at his age can be quite harsh and scary for the parents though, and as the father of three myself, I saw this reaction many, many times.
Realize that Zander thinks in an imaginative world that seems totally real to him. Use that to your advantage. We created invisible "sprays", light switches that made bugs go away, monster barriers made of paper and tape...anything really that reassures the child that they are safe. It doesn't matter that it is not real or effective to us adults, it is real for him.
Unless Zander shows reactions of a severe nature such as marked insomnia or a consistent more than thirty-forty minute severe fear reaction I think he will be fine. Indeed, some studies I read show that children who have these strong emotional reactions turn out to be adults who possess creative intelligence, the most valued type.
A pleasure helping you. Steven