Question
QUESTION: Hi there! I live in an old cottage in a semi-rural part of north central Maryland. For some reason, this fall, my cottage has become overrun with what appear to be millipedes every night. I read one of your earlier posts about these pests, but wondered what my options were since I have small dogs in the house? Obviously, I do not want to use an insecticide that might be harmful to my dogs (and that can be either breathed in or absorbed through their pads). I'm vacuuming up at least 50 of these things every night. Will their migration eventually stop, or will this infestation continue? I have been unable to locate any nests.


ANSWER: For millipeds the insecticide treatment needs to be done on the outside of the house. Spray a 2-4 foot band all the way around the house making sure you spray any cracks and around the window and doors.

Insecticides are available which are labeled for outdoor use against millipedes and centipedes. These include products containing carbaryl (Sevin WP), bifenthrin (Ortho-Klor Termite & Carpenter Ant Killer Concentrate or Ortho Bug-B-Gon Max Lawn & Garden Insect Killer Concentrate, or Ortho Home Defense Max Perimeter & Indoor Insect Killer Ready-To Use), lambda-cyhalothrin (Spectracide Triazicide Once & Done! or Spectracide Bug Stop Indoor Plus Outdoor Insect Killer Ready-To-Use or Spectracide Triazicide Once & Done Insect Killer Ready-To-Use), cyfluthrin (Bayer Advanced Power Force Carpenter Ant & Termite Killer Plus Concentrate or Bayer Advance Home Pest Control Indoor & Outdoor Insect Killer Ready-To-Use), esfenvalerate (Ortho Bug-B-Gon Multi-Purpose Insect Killer Ready-To-Use), deltamethrin (Bayer Advance Power Force Carpenter Ant & Termite Killer Plus Ready-To-Use). Apply insecticides around the outside of the home concentrating where millipedes and centipedes may live or enter the structure. Treat the lower 2 to 3 feet of the foundation wall, as well as a band of soil 2 to 4 feet out from the foundation. Applications should be made with just enough water for the insecticide to penetrate through mulch and thatch to reach the soil. Although pesticides are available for indoor use, removal with a vacuum or dustpan and broom is often sufficient. Before using any pesticide, read the label carefully and follow directions and safety precautions.

---------- FOLLOW-UP ----------

QUESTION: Thanks very much. However, I worry that even outside applications of insecticides may affect my dogs, who are walked in the cottage yard several times a day/night.

Should I elect not to spray, will the migration end anytime soon?

Answer
Migrations may be caused by:

Population Pressure. As numbers increase in an area, the competition for food and harborage forces some part of the population to seek other sites.
Destruction of Habitat. Movement may occur during construction. As habitat is destroyed, the millipedes will seek other sites.
Standing Water. After long periods of rain, standing water may force millipedes from low lying areas.
Although any of the above may be involved, population pressure is probably the main reason for mass movements of millipedes. Movement is always at night. A person may clean up in the afternoon and by the next morning hundreds have again accumulated. Another problem that one may encounter is that some may think that they are trying to get in the house and that's not the case-it's just that the house gets in their way and invariably a few will get into the house. They may enter though weep holes, around service lines or around loose fitting windows or doors. Once they enter the house, they will soon die due to the dry conditions which occur in most air conditioned buildings. Although there may some odor associated with these animals, the number one problem is probably one of nuisance-just the thought of thousands of anything occurring on ones property is somewhat unsettling.

It will not last long if you can with stand the invasion. Based on the outside temperature and moisture. The millipedes can not stand the drier air inside and will die. The insecticide once dry will not effect the dogs.