Easy; they just _look_ like insects. They're actually delicate, beautiful creatures with liquid ammonia blood and exoskeletons made of transparent crystalline water-ice that scintilates in their homeworld's dim white sunlight. They speak with chiming tones and make a sound like tinkling glass as they dance across the glacial plains and swooping arches of their cities.
And then give them a bloodthirsty, xenophobic culture dedicated to chaos and destruction. Make it your trademark to radiation-bomb enemy homeworlds, use plague weapons, the whole nine yards.
I love coming up with races.
