Sweat Bees

Sweat bees (Figure 1) are solitary insects that busily visit flowers to collect pollen and nectar that they carry back to their burrows. Many species in Kentucky have dark bodies while others are bright with a metallic sheen. Females can sting if threatened or mashed but are not randomly aggressive. The bees are attracted to sweat on the skin; they will land to collect some of the salty liquid to supplement their sugary diet. Thus, the potential for conflict and an occasional sting.

Individual reactions to stings vary. Often, the pain is short-lived, but occasionally there may be large, localized swelling, or even a systemic reaction. According to a study evaluating reactions to sweat bee stings, hypersensitivity to their venom is distinct and not associated with reactions to other stinging insects.

Hover Flies

Corn flies, hover flies, bee flies, or helicopter flies (Figure 2) are among the common names for several species of hovering bee mimics that also enjoy a salty liquid snack. These persistent two-winged insects use sponge-like mouthparts to blot-up sweat. They are annoying but do not have stingers. The larval (maggot stage) of many bee flies are predators that feed on aphids. Some species feed on corn or grass pollen.

Figure 1. Sweat bee visiting a flower (Photo: Lee Townsend)

Figure 2. Hover flies, also known as corn flies or bee flies, cannot sting (Photo: Curtis Judy, Todd County Extension agent)



Velvet Ants

Velvet ants (Figure 3) are striking insects clothed in red and black or orange and black “hairs.” Females are wingless; males have two pairs of black wings. Females have very long stingers; the potency of the punch they pack is reflected in one of their common names – “cow killer wasps.” Picking one up can provide a memorable experience. These wasps, seen walking determinedly across the lawn, do not have a home, so there is no place to retreat. They pose no threat unless handled or stepped on by bare feet.  For more information, refer to UK Entomology fact sheet, Velvet Ants (ENTFact-442).

Stinging Caterpillars

Stinging caterpillars are armed with hollow spines that break off easily into the skin of anyone who accidentally brushes against them. Irritating chemicals released from these tiny needles can cause reactions that vary from mild irritation to severe pain, and occasionally anaphylactic shock. Many of these caterpillars advertise with bright warning colors – red, yellow, orange. You can see common species in this publication: Stinging Caterpillars (ENTfact-003).

Figure 3. Velvet ant (cow killer) and stinger (upper left) (Photo: Lee Townsend, UK)

Figure 4. Avoid contact with spiny, hairy, or brightly colored caterpillars, such as this American dagger moth caterpillar (Photo: Invorma,

First Aid Tips

Here are some first aid tips for dealing with caterpillar envenomation (from Medscape):

  • Wash the affected skin immediately with soap and water, and dry it without contact (e.g., use a hair dryer).
  • Apply local cooling measures to reduce pain. This may be enhanced by applying topical isopropyl alcohol or ammonia.
  • Exposed eyes should be immediately flushed with a large volume of water.
  • Use sticky tape (especially duct tape) to remove caterpillar hairs and bristles from the skin.
  • See a physician if acute symptoms develop. Anaphylaxis should be treated in standard fashion.
  • Arms or legs exposed to caterpillar stings should be splinted and elevated, apply ice to reduce pain.
  • Remove any potentially constrictive jewelry before swelling progresses.


By Lee Townsend, Extension Entomologist



Posted in Human Pests