Despite their primary purpose being to provide dye crafting material, these can do substantial damage, especially to players who mistake them for passive Critters.
The Cyan Beetle spawns rarely and can be hard to spot due to its small size and blue color which blends well with the Snow Biome. Use of Water Candles, Battle Potions and Hunter Potions is recommended when trying to hunt it for the Cyan Dye.
The Cochineal Beetle and the Lac Beetle exists in real life, but they are a scale insect, not a beetle. It secretes lac, which can be used as dye or converted into shellac, a brush-on colorant, food glaze and wood finish.