Ladislas Starevich (Władysław Starewicz) was an amazing animator who used real insects (he'd worked in a museum and wanted to film beetles fighting) as stop motion puppets. He went on to have an great career - THE MASCOT is probably his best known work.
I just picked up the Image compilation of his shorts, THE CAMERAMAN'S REVENGE & OTHER FANTASTIC TALES.  Great collection but, sadly, it's now only sold as a DVD-R.  (Which came as a surprise, as there was no mention of the change in formats on the packaging or on Image's website.)