The poisonous insects infecting Fū.
Nano-sized, poisonous insects (ナノサイズの毒蟲, Nanosaizu no Dokumushi) are used by some members of the Aburame clan as part of their Destruction Bug Host Technique. Unlike the standard kikaichū, which are able to act independently of the user, the nano-sized insects can only be transferred on to a victim's body by direct physical contact, though only a mere touch from the user's skin is required as the bugs can circumvent most forms of clothing. However, this apparently does not apply to the user's own clothes, who must instead remove items in order to effectively increase the transferable surface area of the technique. Once an opponent is infected with these bugs, they suffer excruciating pain until the bugs are removed.
The two known users of these bugs, Torune and Shikuro Aburame, are also the only Aburame to possess the antibodies for the insects.