Spring is when most insects begin to be most active. Fire ants, Isopods (pillbugs), and spiders are very common around homes during the spring. Wasps are also very common in eaves and doorways. Structure infesting ants such as little black ants, pharaoh ants (sugar ants), crazy ants, and carpenter ants will be seem with much more frequency.
Rodents also will breed more actively during this time of year.