HONG KONG —Swarms of aggressive giant hornets, in their fall mating season, have killed 42 people and injured 1,675 others in three Chinese cities in Shaanxi province since July, CNN reports.
 

According to government officials, 37 patients remain in critical or serious condition from hornet stings. Since the summer months, hornets have invaded schools and descended upon unsuspecting farm workers in China.
 

In central China, 37 patients remain in critical or serious condition after attacks from the hornets, which are as large as a human thumb.
 

The influx of venom to the human body can cause allergic reactions and organ failure leading to death. Patients have been receiving dialysis to remove the toxins from her body.

Authorities say these attacks are from a particularly venomous species known as the Asian giant hornet or vespa mandarinia, which has an orange head with a black tooth used for burrowing.
 

Dr. Wang Xue, director of the intensive care unit at First Affiliated Hospital of Xi'an Jiaotong University and an expert on hornet stings, warned in a government release that hornets tend to be aggressive and more active during September and October, and do not go into hibernation until December, CNN reported.
 

Thousands of police officers and pest control contractors have been dispatched to destroy the hives. Unusually dry weather in the area may be boosting hornet populations, authorities say. Urbanization could also be a contributing factor, as humans move into hornets' habitats.