Enzymes that rapidly break down plastic bags have been discovered in the saliva of wax worms, which are moth larvae that infest beehives. The enzymes are the first reported to break down polyethylene within hours at room temperature. The discovery came after one scientist, an amateur beekeeper, cleaned out an infested hive and found the larvae started eating holes in a plastic refuse bag. The researchers said the study showed insect saliva may be "a depository of degrading enzymes which could revolutionise [the cleanup of polluting waste]". Polyethylene makes up 30% of all plastic production and is used in bags and other packaging that make up a significant part of worldwide plastic pollution. The only recycling at scale today uses mechanical processes and creates lower-value products. Chemical breakdown could create valuable chemicals or, with some further processing, new plastic, thereby avoiding the need for new virgin plastic made from oil. The enzymes can be easily synthesised and overcome a bottleneck in plastic degradation, the researchers said, which is the initial breaking of the polymer chains. That usually requires a lot of heating, but the enzymes work at normal temperatures, in water and at neutral pH. Previous discoveries of useful enzymes have been in microbes, with a 2021 study indicating that bacteria in oceans and soils across the globe are evolving to eat plastic. It found 30,000 different enzymes that might degrade 10 different types of plastic.