bug bites on my head?

i've been having bug bites or something on my head for quite a while. i don't know what's biting me. where i live is pretty open, but my parents always have some exterminator come over. i told my friends, but they just said to put some disinfecting spray on it. didn't work well. what should i do to get rid of them?

please no telling me to go to the doctors btw...