Myrmecophobia is the inexplicable fear of ants. It is a type of specific phobia. It is common for those who suffer from myrmecophobia to also have a wider fear of insects in general. Such a condition is known as entomophobia. This fear can manifest itself in several ways, such as a fear of ants contaminating a person's food supply, or fear of a home invasion by large numbers of ants.

The term "myrmecophobia" comes from the Greek , "myrmex", meaning "ant" and , "phóbos", "fear".

Entomophobia (also known as insectophobia) is a specific phobia characterized by an excessive or unrealistic fear of one or more classes of insect, and classified as a phobia by the DSM-5. More specific cases included apiphobia (fear of bees) and myrmecophobia (fear of ants). One book claims 6% of all US inhabitants suffer from it.

Entomophobia may develop after the person has had a traumatic experience with the insect(s) in question. It may develop early or later in life and is quite common among the animal phobias. Typically one suffers from a fear from one specific type of insect, and entomophobia leads to behavioral changes: the sufferer will avoid situations where they may encounter the specific type of insect. Cognitive behavioral therapy is considered an effective treatment.