Why are nerds bullied?

"Nerds" are bullied to feed the ego of the bullies : they see themselves as dumber or inferior and try to physically belittle or intimidate to make themselves feel better.

This doesn't just apply to "nerds" : bullies pick on those smaller, weaker, or just different than they are.

To avoid bullying, try this:

1. Avoid the people that might be a threat to you. If necessary, change your schedule or routine.

2. Make some friends, or change your look. Act confidently.

3. If bullies are after you, friends, teachers, and supervisors can discourage them.

(see related question)

Basically they are small and scrawny and have no defense. This presents the bullies with little risk of being defeated or embarrassed.