Contrac All-Weather Blox Rodenticide - Questions & Answers

Contrac bait should be stored at room temperature and replaced every 40-60 days in the bait stations because it contains food based ingredients. The bait could mold or sour in the hot or cold months (should be replaced every 30 days during the summer and winter) and may be less palatable to the mice. It should eradicate the mice if they consumed enough of the bait.

There is no defined time for the Contrac Blox to breakdown. The more moisture and direct sunlight the exposed blocks receive, the faster they will breakdown. The actual active ingredient will last until the bait has disintegrated. For future baiting it is important to secure the bait so that it cannot be carried off. If baiting in an inaccessible area you can lace the blocks on to a thick wire so it cannot be moved. If the bait is used in an exposed areas you can secure it in tamper resistant bait stations.

Contrac does not contain glass. It contains food based ingredients that attract the rodents to the bait for consumption. It is an anti-coagulant which means once the mice eat this product they begin to bleed to death from the inside.  The mice first become sick, and then grow tired and weak and pass in their sleep.  It can take anywhere from a few hours to a few days depending on how much the mice have eaten.  They do not need water for the product to work.

While we are not the manufacturer of the Contrac blox we do carry another product that is for use in areas where secondary poisoning of predatory birds are an issue.  Terad3 rodenticide is usually used in areas where secondary poisoning is a concern because it has a reduced risk of secondary poisoning.

Below is a few helpful hints for baiting Mice.

• Always use fresh bait. Rodents will avoid old, moldy, or insect-ridden baits.

• When baiting for mice, a good measure for distance between placements is 8 to 12 feet apart for light to moderate infestations. Heavy or severe infestations may require placements of 4 to 8 feet.
  
  

• As a rule, many bait placements containing smaller amounts of bait are more effective in mouse control than a few placements containing a lot of bait.
  
  

• For heavy infestations, use the maximum number of bait placements indicated by the label.
  
  

• Bait stations should be placed where mice are likely to encounter them during their routine travels, between harborages and food sources.
  
  

• Corners are "hot spots" for bait placements since mice tend to spend a lot of time in darkened corners.
  
  

• Attempt to locate "favorite feeding locations" (indicated by a high concentration of rodent signs-droppings, tracks, odors, shredded paper, etc.) and replace existing food sources with bait stations in these locations.
  
  

• Always use mouse-sized bait stations, not the larger stations designed for rats.
  
  

• Mice often live above or below their food sources, in attics or basements, so bait placements should not be limited to a single level of the infested structure.
  
  

• Mice develop preferences for certain types of foods and baits. If there appears to be bait avoidance, try placing 3 or 4 different bait formulations (pellets, place packs, bait blocks, liquid bait) to see if the mice will prefer one formulation over another.
  
  

• If a bait placement remains unvisited upon inspection, try moving the placement five feet in another direction.

When treating for rats outdoors, we always recommend that you use tamper resistant bait stations that will help stop accidental poisonings of non-target animals and children no matter which bait you select.  Please take a moment to read our article for baiting tips for rats. We would recommend to use Contrac blox which will kill the rats within 1-5 days after a single feed.

Contrac is a block rodenticide that does not release any vapors. If applied in tamper resistant bait stations it should pose no harm to humans if applied as directed.

We apologize, we could not open that link. We would recommend to please send us a clear picture of the rodent droppings or contact your Cooperative Extension Office.

Contrac Blox is a single feed rodenticide. Single feed means a rodent can consume a lethal dose of Bromadiolone in 1 feeding therefore resulting in death within 1-5 days. The number of rodents that 1 block will treat is undeterminable. Place 3 to 16 Contrac Blox (usually at intervals of 15 to 30 feet) per placement. Maintain an uninterrupted supply of fresh bait for at least 10 days or until signs of rat activity cease. Replace contaminated or spoiled bait immediately. Collect and dispose of all dead animals and leftover bait properly. To prevent reinfestation, limit sources of rodent food, water, and harborage as much as possible. If reinfestation does occur, repeat treatment. Where a continuous source of infestation is present, establish permanent bait stations and replenish as needed. 

Contrac Blox Rodenticide uses human food grade attractants. There is potential for roaches to be attracted to the sent. Yes, they could harmed from eating the poison. To treat for roaches, we recommend to use one of our Roach Control Kits.

For a rodenticide, we would recommend Contrac Blox. It is a single feed kill. It comes in an 18 lb. pail. We would recommend putting these in rat bait stations, such as Protecta Rat Bait Stations. If you are in CA, we would recommend Fastrac Blox. Although they are not a single feed kill, they still will work wonderfully.

For spiders, we would recommend using Bifen IT. This can be sprayed indoors and outdoors. It does have a residual of about 90 days indoors and 30 days outdoors. Indoors, it needs to be sprayed in the cracks and crevices and along the baseboards. Outdoors, this product can be used around the perimeter, in the lawn, on shrubs, trees and on flowers. This product should be used on edibles.

Insects are trying to fatten up for the winter. It is not uncommon for insects to be more attracted to rodent bait like Contrac. We recommend to sprinkle Niban Bait around the outside perimeter of the bait station to keep the insects out.

Contrac Blox Rodenticide do not emit any type of vapor. This product should not cause a reaction to a child unless they come in direct contact with it. Contrac Blox should be placed in tamper resistant bait stations. It will pose no threat to humans if it is used as directed.

Rodents that eat the ContracBlox will not neccessarily go outside to die. There is a high possibility they will die indoors and then you will be dealing with a very foul odor for atleast a few weeks. We would recommend trapping rodents indoors using snap traps or glueboards. Trapping eliminates odor problems by allowing you to dispose of the carcass. Please read over our article regarding eliminating rodents indoors.

It is a poison so if it is injested, it is likely to harm whatever is injesting it.

Each blox of Contrac is 28 grams which equal 2800mg. If your pet ate an actual blox, I wouldn't take the chance of figuring it out because the minimum amount could be lethal. It would be best to take your pet to the vet and have him/her take a look and/or administer the antidote which is Vitamin K1.

Contrac Blox Rodenticide is not labeled to treat for chipmunks we cannot recommend it. Please visit our Chipmunk control page. 

To our knowledge Contrac Blox are not labeled for Voles. Kaput Combo Mini Blox is labeled to be used for voles and would be a better option when used in bait stations. Voles: Place 1 block in each bait station. Situate bait stations near runways, burrow opening or plants that voles have been damaging. Check placements daily. Maintain a fresh bait supply for 15 days.