Subject: Mouse eating bugs
Location: Newmarket, Ontario, Canada
August 2, 2012 8:30 pm
It’s summer here, August 2nd, and I found these bugs outside in the evening devouring a dead mouse. They could fly, and occasionally they would fight each other. Also, it appeared as though they may have been carrying their babies on their back. They were incredibly active, especially when fighting with each other, any idea what they are?
These are Burying Beetles or Sexton Beetles in the genus Nicrophorus, and Burying Beetles are best know for burying small dead animals and guarding the corpse while their larvae develop in the putrefying flesh. It appears this mouse is on concrete, and the Burying Beetles are unable to bury it on site and it is too heavy for them to transport. The babies you mentioned are most like Phoretic Mites which use the Burying Beetles’ ability to fly to hitchhike to a new food source. The mites will feed on maggots and fly eggs so this is a symbiotic relationship between the Burying Beetles and the Phoretic Mites. The Mites get transportation and the Bury Beetles benefit because there is more rotting flesh for their young, ensuring that more larvae will have enough food to mature and perpetuate the next generation. You can get additional information on Burying Beetles on BugGuide.