A tick species that arrived in the Western Hemisphere in 2017 can reproduce quickly. And researchers from the U.S. Centers for Disease Control & Prevention are now sounding the alarm that Asian longhorned ticks are spreading across the United States.In the video player above: See what the Asian longhorned tick looks likeThe CDC warning comes after three cows in Ohio died after being bitten tens of thousands of times. An analysis published in the Journal of Medical Entomology reveals that scientists gathered nearly 10,000 ticks in around 90 minutes at the cow pasture.Asian longhorned ticks have been found in 19 states. Along with being spotted in Ohio, the invasive species has been seen in Arkansas, Connecticut, Delaware, Georgia, Indiana, Kentucky, Maryland, Massachusetts, Missouri, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, And West Virginia.According to researchers, the ticks can reproduce quickly, hide in tall grass and survive harsh conditions. It’s unclear if the ticks can pass diseases to humans, but the CDC's website states that compared to native tick species, the Asian longhorned tick "appears to be less attracted to human skin." However, the CDC website also states that Asian longhorned ticks have been found on pets, livestock, wildlife, and people.According to the U.S. Department of Agriculture, the ticks are native to eastern China, Japan, the Russian Far East, and Korea.In a "Pest Alert" the USDA describes the Asian longhorn tick as "an invasive pest that poses a serious threat to livestock."The ticks "are light brown in color and are very small, often smaller than a sesame seed," according to the USDA Animal and Plant Health Inspection Service website, which also explains that female Asian longhorned ticks can reproduce without a male, and that "it only takes a single tick to create a population in a new location."