Of course, there is a difference in the Spring. In the warming days of spring, many things come out that have been hybernating all winter. Snakes and lizards suddenly come out from nowhere. A good suggestion here, is to use moth balls, scattered about your yard, garden, and underneath your house.
Mosquitos start early in the year by having standing water and other factors. Putting a few drops of clorox into standing water, or even in chicken water, will help to control the problem.