There are two popular interpretations about dreams that involve a lot of snakes. A dream about being surrounded by snakes could mean that you're feeling overwhelmed, or it could symbolize an abundance of energy.
Snakes As A Sign That You're Feeling Overwhelmed
This interpretation doesn't need much of an explanation; being surrounded by wriggling, slimy things is quite a daunting prospect! Your reaction to the snakes, and how many there are, could be an indication of just how overwhelmed you're feeling. You might also want to consider what else was happening in your dream at the time. For example, if you were at school when the snakes appeared, this could be a sign that you're feeling overwhelmed by the amount or difficulty of your school work.
Snakes As A Symbol Of Excess Energy
Snakes are living creatures and they tend to move pretty fast. If you dream that you're surrounded by them, then perhaps they represent your own energy or desire for activity. Many dream interpreters would say that the energy represented by the snakes is creative or sexual in nature. Interpreting the snakes as symbols of energy makes more sense if the snakes weren't frightening you.