Yellowjacket numbers are extremely high at the base of Sliding Sands trail, where the horse tours usually stop and at Kapalaoa Cabin. Yellowjackets are also present at lower levels at other locations within the park.
Yellowjackets are aggressive and may sting without warning. They are attracted to water, meat, sweets (both food and drink) and sweet-smelling perfume, cologne and sunscreen. They may swarm around people who stop for a snack or meal. Unlike bees that sting once and die, yellowjackets sting repeatedly.
Do not swat at these wasps, as this will only make them more aggressive. If wasps are swarming around you, put away any food or drink and walk calmly away from the swarm.
High numbers of Western Yellowjacket wasps can currently be found in Haleakalā National Park.
Yellowjacket stings can be very painful, and may cause anaphylactic shock in some individuals. Visitors who are allergic to wasp or bee stings are asked to carry necessary medications and consider not visiting problem areas. If a serious reaction occurs, call 911 and go immediately to the nearest medical emergency facility.