Starlings, Mice and Rats are Pests Too!

Posted: January 21, 2008

Del Voight,
Capital Region Pest Management Agent
November 15, 2002

Many people don’t consider that pest management includes other pests besides insects, weeds and disease. Pests like deer, mice, rats and even lice are overlooked as pests and that they too should be managed using an integrated pest management approach. Under this system of management as in field crops the pest is monitored to determine populations the estimated cost of control is measured against the economic impact of the  damage that may occur from the pest. After the likelihood that a benefit will be realized does a treatment or action be taken to eliminate or reduce the population to a manageable level. This article will brief some Integrated Pest Management ideas for starlings, mice and rats all of which may be nuisances, spread disease(salmonella) and consume large amounts of feed targeted to livestock.

Mild winters and the lack of enough predators along with ample food sources on farms  has caused widespread growth of Starling populations. A survey conducted by Jason  Suckow of the US wildlife service in cooperation with Paul Craig and other Extension
Agents found that of the 155 respondents from 22 counties 57% rated problems with birds as severe or very severe and that Starlings were the #1 pest – 94%. Here is some general biological information known about the pest. They are cavity nesters (trees,
buildings) and will compete for these sites, each female will lay 4 to 7 eggs that hatch in 11 to 13 days and the new hatchlings will fledge at 21 days of age and then provide a second nesting.

They will consume 50% (@3.5ounces)of their body weight. For example let’s look at one farm with a population ranging from 500 to over 1000 this equates to about 100 to 200 lbs of that farms feed lost per day! I might add that they tend to eat the best feed. If the feed lost was corn for example then simply calculate the loss. 100 lbs of corn would be worth about 4 dollars and at 200 lbs would be 8 dollars lost per day or $1460 to $3000 dollars lost per year from a moderate population of birds. Does
it pay to take care of this pest? There are estimates on some farms of over a million birds…. an obvious problem. Analyze your own farm and do the math to find out how much you might be losing. Since it is a problem on many farms what can be done to alleviate the problem. Exclusion, cultural and habitat modification, frightening, repellants, toxicants, trapping, and shooting are ways to eliminate the birds and each are effective depending on the operation and the extent of the problem. To determine which is best for your farm Jason Suckow is available to answer those questions and he can be reached at 717-728-0400. There are also licensed for hire control specialists that may
assist you in managing the bird populations. A fact sheet discussing the issue of nuisances birds is available at your local Extension Office. As many of you know Starlicide Complete was once again labeled in Pennsylvania for bird control and this product is only as effective as the producer is dedicated and understands how to use the product and properly pre bait the birds. Winter is the best time to eliminate populations and plan now to be ready for the mid winter control measures that will need to be taken. Rats and mice also are nuisances on farms.

Here are some interesting tidbits of information presented by Paul Craig at a recent crops day event:

  • In a sample of 1000 grain samples – 76% contained rodent droppings hair food contaminants.
  • One mouse produced 36,000 droppings/year and one rat produced 25,000 droppings/year.
  • A rat eats 30 to 40 pounds food /year and contaminates 10 times as much not to mention structural damage which mice are especially known for doing on farms.


Important biological information known about rats and mice helps in determining management systems:

  • Mice are mainly nocturnal and limited daytime activity they have poor eyesight, rely on smell, taste and touch, and are colorblind.
  • The life span of a mouse is 12 to 15 months and their home range – is only from 9 to 30 feet. Sexually mature at 45 days they will rear a litter size of 3 to 11 born 19 to 21 days after mating and will have 5 to 11 litters per year. Rats on the other hand have been known to be active during the day at high populations.
  • In addition rats grow larger and will live in an area of 20 to 300 feet a much larger range than the mouse.
  • Sexually mature at 90 days rats will raise 8 to 10 young per litter and have 4 to 12 litters/year. They differ from mice in that they are much more sensitive to objects (like a bait station) in their environment and can detect even the smallest amount of poison in baits.

Aside from the logic of cleanliness on the farm and control of weeds and debris (this also includes junk) around the buildings one should monitor populations. To monitor populations it is suggested to build bait stations free of poison or bait and traps that would be checked on a regular basis to determine whether a full-scale control program is needed. If the presence of many mice and rats are noted then it is suggested to begin a control program. A tube of @2 inch in diameter leading into a covered box placed near shelter and travel routes allows for only the mice and rats to enter and keeps cats out. Too short of baiting periods, insufficient bait and replenishment, too few bait stations, too far apart (Mice – 6 feet apart), too small an area treated, too many easily obtained food sources available, tainted baits (wear rubber gloves) are all reasons for failure in the baiting procedure. Again, the Extension Office has fact sheets detailing the proper
management of rodent populations and one can call the Extension Office for more information or there also are many specialists available that for a fee will monitor and treat rodents on farms.

By monitoring pest populations to avoid population explosions and by calculating the relative cost of control versus the loss of feed one will soon find that managing both nuisance birds and rodents makes economic sense.