Pest Control Questions Answered

Expanded Question:

Hello.  I am horrified that I apparently have rats in my older (built in 1930) home.  This has not happened in over 9 years.  I recently observed 2 rats run on the electrical line to my roof & have since then observed rats in various areas of the roof (near the gutter line). I have been hearing noises in the attic, walls, & behind cabinets for a while now.  Also, my house is pier & beam so there is a crawlspace & I have heard something "furry" rub against the bathtub (that pretty much sent me running & I have now begun having nightmares). I am a female living alone on disability with limited help.  I want to hire a pest control company & have made calls but can't determine which is the best way to remove them...by using traps or poison bait stations.  I am afraid with the poison they may die in the walls.  Also I have 3 cats & I am concerned that they could somehow be poisoned.  Which do you recommend?  Also, as far as preventing further entry what do you advise?  Is there any way to prevent them from coming over the utility lines in the future?  What sort of repairs/damage should I look for that they could have caused while they took up residence here?  ANY HELP IS VERY MUCH APPRECIATED!!

Answer:

Rats displaying the behavior that you describe, indicates that you have roof rats.  You must be living near the Southeast or West Coast, or along the Southern coastline.  Roof rats cannot survive where the predominant Norway rat presides, which is more Northeasterly, but is also found throughout the Country as well.  It seems that roof rats are better able to operate in the warmer climates, and remain aloof from their Norway rat enemy, which is not as capable a climber by comparison.

Before you attempt to seal rats out of your home, you should get rid of the present dwellers.  I like baits because this approach is less labor intensive, and trapping approaches being an art form.  If you choose baiting, necessary precautions can be taken to avoid injury to child and pet.  Fundamentally, over baiting is preferred to multiple bait replacement.  When rats find an ample food supply, they are less apt to avoid the bait because of the competition factor which keeps less dominant rats at bay.  Anticoagulants also lead to odor from dead rats but less intense than a quick killing product because the blood is less likely to congeal, allowing gases to escape, with less bloating following death.  For the most part rats, feeling weakened, may return to their nesting site.

With roof rats, prebait the traps unset, and allow the rats to familiarize themselves with the trap as a safe food source.  Set multiple traps, all having been prebaited, using fruits, nuts vegetables and tying down the traps so that they remain in place.  Set the traps after a few days of feeding the rats in this fashion, and you may catch all of them.  Place the traps in new locations after the first catch so that the location does not effect association with previous danger.

If you can, hire a professional, it'll be so much easier on you.

Rat, and mouse proofing should then follow.  All holes cracks and crevices that are larger than 1/4 inch should be closed with sheet metal or galvanized wire mesh and then mortared with a mortar mix with 5% of its total volume having added Portland cement.  In other words 95% mortar mix to 5% Portland.

Laura, please contact me if my answers are inadequate, and I'll expand this discussion further.

Best wishes,

George Manning
Consulting Entomologist

Pest Control Chicago