Cruciferous plants use a sophisticated defense system, known as the mustard oil bomb, to get rid of their enemies: If plant tissues are wounded, glucosinolates and an enzyme known as myrosinase come into contact, and, as a result, toxic metabolites are formed which deter most insects. This mechanism, however, has no negative effect on flea beetles, according to scientists. Flea beetles are even able to sequester glucosinolates without the mustard oil bomb being set off by the plant’s enzyme.