Boxelder bugs overwinter in soil and plant materials and emerge as adults in the spring as weather
warms. Outdoors they are not a major plant pest. The insect becomes an issue with homeowners when
they try to move indoors in the fall, searching for overwintering sites. Boxelder bugs lay eggs that hatch in late July and become a problem when the insects look for shelter in cracks and crevices on houses as weather cools. When they enter a home in large numbers they can become a nuisance, staining curtains and walls with their excrement. Crushing Boxelder bugs can leave a large red stain on walls or curtains. The most effective control of Boxelder bugs is stopping them before they enter a home. This can be done by sealing cracks and gaps in windows and doors, or by applying a chemical barrier around the home that kills them before they enter your house.

Outdoors, Bonide Ant Killer Granules create an effective barrier to the insects as they climb up from the ground, seeking a way in.

If the insect becomes a problem indoors, these Bonide products are labeled for control in homes: Household Insect Control RTU, Household Insect Fogger, and Cyper Eight concentrate. Effective management and exclusion outdoors significantly reduces the number of insects that will be a problem indoors.


Boxelder Bug Facts:

  • Enter homes seeking warmth to overwinter
  • Insects do not reproduce inside homes
  • They do not bite people
  • Can exist as nymph, or adult during the same time of year
  • Can stain curtains or walls when crushed or through excrement
  • Best time to control is in late summer and early fall when insects are massing around the exterior of dwellings
  • To remove dead insects indoors, vacuum and remove vacuum bag immediately afterward to avoid unpleasant odor
  • The best management of Boxelder bugs is prevention