ANSWER: Sun Spots found the following information at Cornell University’s Web site.

D-Con, also known as warfarin, is a chemical rodenticide ready-to-use in a mixture of cornmeal or other material. Its principal use is as an anticoagulant that is highly effective in controlling rats and house mice. It is odorless, tasteless and effective in very low dosages. Action is not rapid, usually about a week is required before a marked reduction in the rodent population is effective.

Warfarin has found ready acceptance because rodents do not tend to become bait-shy after once testing the material. They continue to consume it until its anticlotting properties have produced death through internal hemorrhaging. No pre-baiting is needed since there is no bait shyness. Repeated ingestion is needed to produce toxic symptoms. Continued eating counters the action of Vitamin K in the body. It can be used continuously year after year wherever a rodent problem exists. Mice are harder to control than rats, and complete control may take a longer period. Resistant strains of rats and mice have developed.

The following advice to help rodent-proof your home also was found on the Web:

1. Inspect your property regularly for signs of rodents. Look for telltale droppings both inside and outside of your home.

2. Remove sources of water, food and housing from your closets, attics and gardens.

3. Keep trash bins covered.

4. Store cupboard food in metal bins.

5. Remove wood piles, junk sheds and garden debris that attract rodents to nest on your property.

6. Turn the contents of your compost bin regularly and check to make sure no critters have been feeding there.

7. Seal up small holes around pipes, vents, doors and windows with 100-percent silicon caulk.

8. Set mouse and rat traps in problem areas. Both live and snap traps are effective and can be baited with foods such as cheese and bread. Release live animals as far away from human dwellings as possible.

9. Lay glue boards in pathways that rodents travel as an alternative trap.

10. Use a natural rodent poison as a last resort. Look for brands of rodent bait made with Vitamin D3. Rats and mice eating a small amount of this vitamin suffer heart failure within days. There is no chance of secondary poisoning of your pets even if they find and eat the dead rodents.

11. Place the bait in areas that rodents frequent.

Tip: Get a cat to keep rodent infestations down. Note that cats are not selective about their prey and throughout the United States are destroying songbird populations. Although it is hard to keep tabs on outdoor felines, try to discourage the capture of wild birds.

Warning: One big problem with using bait is that the rodents often die in inaccessible places. Prompt removal of dead critters is mandatory to avoid a foul odor.

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