In Massachusetts, we deal with mice all year-round, but get an uptick in activity in the fall, particularly for homes in wooded areas. This is in part due to the deer mice living in those areas, which are likelier to want to get inside as the weather turns. New England also has one of the densest tick populations in the world, and people and pets are at risk of tick bites whenever there is no snow on the ground. Mosquitoes are similarly common from around April to October. Massachusetts gets cases of West Nile Virus every year, which is transmitted to humans by mosquitoes that have fed on birds. Cases are most common in August and September, which may be because this is when many bird species fly south, leaving the mosquitoes to find alternative food sources. Carpenter ants, odorous house ants, and pavement ants are a common pest that become active starting around April or May, although sometimes they remain active indoors during winter. An exterior liquid treatment of the foundation in springtime is typically sufficient to prevent them becoming a problem for the year. If left unchecked, carpenter ants can cause major structural damage, though not typically as severe as termites, which are a threat year-round. Wasps (including hornets) will start to form their nests during spring, but tend not to bother people until summer and fall - the small nests formed early in the year do not yet have many workers to defend them, so they are more reclusive. As the year goes on the nests grow in size and aggression. Activity peaks around September, and usually sharply declines by November.
