Sacramento once had more trees per capita than any other US city. We also have an endemic issue with roof rats and field mice. What do the two issues have in common? Trees give access to the rats and other critters that enter your attic via the roof. These uninvited house guest can cost you thousdands of dollars to abate and clean-up their biologically unsafe mess.
We know this due to the number of calls we receive asking "what to do?". Recently, we had such an uninvited guest(s) ourselves and I learned some things that the reader may find helpful.
1. It would be difficult not to know that the guest has arrived: First the scratching on the kitchen ceiling; then the gnawing of our plastic dust pan in the closet. I set one Victor Rat Trap (a scary strong spring-loaded large trap - enough to make one leery of the critter you are seeking!) and over-night caught the 8" long rat who was actually pretty cute, less the blood and surprise look on his/her face.
2. In searching for other options for how to handle the situation, I discovered a web site in my search of wildlife control, which led me to Professional Wildlife Removal. The map of the US and California produced several northern California wildlife control contractors who can rid or relocate critters for you.
3. Further searching led me to a nifty idea for rat or mouse abatement: the Rat Zapper Ultra. Best price on the internet was found at the National Marine Products. This product uses four (4) D-size batteries and produces an electrical shock that kills the critter(s), time, after time, after time. One set of batteries will produce over 200 uses. This is especially good since mice and rats seek shelter for their mates and families as well as themselves.
CONCLUSION: You can have someone else deal with this problem for you (I did not seek quotes for their services) humanely or fatally - your choice. Or, you can trap them yourself as soon as you become aware of their presence in an attempt to minimize the damage to your attic or other structures.
THE BIOLOGICAL ISSUE: Field mice and rats have the potential of infecting humans with hantavirus that is uniquely transmitted by aerosolized rodent excreta or rodent bites. Makeup air in most homes is primarily supplied by both the crawl area and or the attic of a home or the attic alone if the home is build on-grade (concrete slab).
Please feel free to call me if you have any other questions about attics or crawl spaces. You now know everything I know about rats and field mice!
Charles E. Cassani, CR
Steamatic of Sacramento, Inc.
(916) 386-8191