Why did God make bugs?

I remember asking that question as a child, and thinking, if given the chance to make a world, I would make a bug-less one. I couldn't help but remember these childhood thoughts as I read about the new "synthetic" life scientists are trying to create and came across this line: "scientists want to create new kinds of bacterium to make new types of bugs." I may not have understood the ecological ramifications my bug-less world would have suffered, but I certainly do know now that everything man introduces has at least two bad side effects for every good one. I do not want some genetically engineered bug, created by a scientist in his little lab. I am still having a difficult enough time trying not to complain about the ones God made!