During a two year period in Baltimore, most of the mosquitos trapped were either Asian tiger mosquitoes that transmit West Nile, Zika, encephalitis, and denuge fever, or Culex mosquitos that transmit West Nile virus.
A DNA analysis of the blood engorged female mosquitos found that, surprisingly, that rats the most common meal of the Asian tiger mosquito, and they were the second most common meal of Culex mosquitoes, after birds. Humans and cats were next in meal frequency, and smaller amount of blood was taken from deer and dogs.
The researchers believe that the mosquitoes were feeding on whatever was available and easiest to bite. It is amazing that rats are so numerous, that they would be the primary meal of the Asian tiger mosquito in the city.
Researchers also found that the amount of blood mosquitoes sucked from humans differed in various areas of the city. Where people spent more time in their backyard, and their yards had shade, moisture, and lots of plants, where mosquitoes were more abundant, more blood was coming from people than animals.