My fills are always in 8th notes/slower note rates, help!

Most of my fills when soloing or when just playing the song are mostly eighth notes or slower note rates. Sometimes I'll play sixteenths here and there but I have a tendency to stick to 8th notes. I can't seem to get out of it. I usually play what I 'hear in my head' but that means that I'm only 'hearing' 8th notes! What can I do to change this? I don't want to be confined to playing 8th notes all the time.. it gets boring after a while for both me and mainly for the other band members as well. Sometimes I try to tell myself to play more sixteenths when I play but for the most part, I don't even think while I'm playing and for some reason I get stuck in 8th note land. Please help!

My fills are always in 8th notes/slower note rates, help!