The invention relates to a method and projectile for combating nests of harmful insects, the method being characterised in that it comprises: providing a mould with cavities in the shape of a projectile; pouring into the cavities of the mould a pesticidal liquid suitable for the type of insect to be combated; freezing the pesticidal liquid poured into the cavities of the mould; removing the frozen pesticidal projectiles from the cavities of the mould; firing the frozen pesticidal projectiles into the nest; and distributing the pesticidal liquid inside the nest during the progressive thawing of the projectiles at ambient temperature.
