Yellow hornet has a sting which it uses defensively to inject a mild toxin. Adults of this species can sting when they feel threatened, but generally, their toxicity is considered mild. Humans, dogs, and cats may experience temporary discomfort and localized reactions upon being stung. Other insects such as bees and ants may also be affected by the sting, leading to disorientation or deterrence, limiting aggressive encounters. Examples and reactions to the toxin vary across species, with smaller animals possibly showing more acute symptoms.

Yellow hornet typically stings to defend its nest or when threatened, enacting a painful method as a deterrent. Such incidents often occur when humans encroach on their territory. Their stingers, unlike bees, are not barbed and do not detach, allowing multiple stings without self-harm. Notably, only female yellow hornet are equipped with stingers as a means of colony protection.

Yellow hornet may cause troubles to humans largely because of their nesting behaviors. Frequent human-wildlife interactions occur as yellow hornet often nest in proximity to human habitats. When they feel their nests are threatened, they may attack and sting humans multiple times, which can lead to discomfort and localized reactions.

To prevent issues with yellow hornet, maintain a vigilant inspection of potential nesting sites around dwellings. Remove any unused containers or debris that could serve as a nesting place. Consider professional pest control for the safe removal of nests and avoid perfumed products that attract yellow hornet when outdoors.

If after an encounter with yellow hornet one experiences discomfort, clean the area with soap and water. Cool compresses may help to alleviate pain and swelling. It's advisable to remain as still and calm as possible if yellow hornet are nearby to prevent provoking them. During recovery, keeping the affected area elevated and minimizing movement can reduce irritation.