Contrac All-Weather Blox Rodenticide - Questions & Answers

Contrac Blox 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.

Contrac Blox should be used within about 1 year of the purchase date. The active ingredient within the product would most likely stay effective long after 1 year but the food ingredients or the attractants will start to degrade and will no longer be attractive to rodents. Just opening and closing the lid of the storage container would not cause the product to lose its efficacy, but storing the product without a lid could cause it to mold or otherwise degrade. Contrac Blox and Contrac Place paks are essentially the same product just in different shapes and packaging. Contrac Place Paks are very useful for treating mice that love to tear open and gnaw through packaging and the pellets are small enough for them to hold and consume, but the product would eliminate both rats or mice. Contrac Blox work well for both rats and mice by providing them with a large gnawing surface.

Contrac Blox is usually preferred in homes with pets and/or children as there is a readily available antidote in the event of accidental ingestion and because of the reduced risk of secondary poisonings (if one of your dogs were to eat a poisoned mouse). Final Blox is used when a fast clean out is needed as it will kill the rodents a bit faster than the Contrac Blox. Final Blox does have a higher risk of secondary poisoning. We recommend that you use tamper resistant bait stations that will help stop accidental poisonings of non-target animals no matter which bait you select.

No, none of the rodent bait stations come with bait included.  Our most popular bait is Contrac Blox.  We do sell the bait in 4lb and 18lb pails. 

The Contrac Blox should not spoil from the heat, though as you have noticed it will start to melt if it gets too hot. We recommend that you replace the bait if it starts to mold or if insects have started to infest it. Rats are notoriously cautious and suspicious of new food items and some can take several weeks, even months before they will accept it. Are other food sources available to the rats? Try to eliminate alternate food sources if at all possible, rats will continue to feed from the "tried and true" food sources that they have used in the past.  You also need to be sure that you have offered enough bait stations to accommodate the rat population on your property as rats can also be territorial.

Contrac All-Weather Blox Rodenticide is not labeled to be used in burrows at all, only for use in tamper resistant bait stations.  Typically, if none of the blocks are eaten then there is a food competition issue.  If there is other food accessible that is more attractive to the rodents then they will eat the other food first.  This could be pet food, bird seed, food in a garden, etc...  Also, placement of the bait stations are critical.  Were the station placed along the foundation or along edges with holes against the wall?

You should keep replacing the bait until the mice stop taking it. You need to place enough bait out each night so that there is left over bait in the morning. This will ensure that each mouse is able to receive a lethal dose. We also highly recommend securing the blox in a tamper resistant bait station so that the rodents cannot carry the bait throughout the house and deposit the blox in undesirable areas.

Yes. There is not a rodenticide on the market that stops a decomposing rodent from smelling after they die. There are a lot of "old wives tales" that suggest that there are rodenticides that will make a rodent exit the building after they eat the bait, leave in search of water or dry up immediately after death and leave no stench behind. Unfortunately, none of this is true. If a rodent dies, it will smell as it decomposes and the rodent will die wherever it succumbs to the poison which is likely to be is an inaccessible area where the rodent has been nesting. We recommend using glue boards, snap traps or multi-catch mouse traps indoors, so you will know exactly where the mouse has died and can remove it with ease.

When please in Contrac Blox a tamper resistant bait station, it will be kept out of direct sunlight and out of the rain. Lots of rain or extreme heat will cause the bait to deteriorate faster than cool dry weather. Basically, bait that is placed into a station should be inspected every week or every other week It should be replaced if it is moldy, melted, sour or infested with insects.

Contrac Blox contains food ingredients that attract rodents. The rodents then consume the bait. When they receive a lethal amount of bait, they will then expire. Rodent baits should be used in tamper resistant bait stations to avoid accidental contact with children and non-target animals.

You can use any of our rodenticides such as Contrac Blox to eliminate pack rats. You should place the Contrac Blox inside of tamper resistant stations to secure the blox so that the rats can not carry them away to unsecured locations. Be sure to place plenty of stations out as this type of rat can be territorial and will stop other rats from visiting certain stations.

Unfortunately, because Contrac Blox are not labeled for gophers we cannot recommend that you use this product for this pest. The only baits that we have for gophers of any kind are ZP Rodent Bait and Hi Yield Mole and Gopher bait. They are actually lableled only for 'pocket gohpers'.

We recommend that you call your veterinarian immediately. We have linked the Contrac Blox product label and the Contrac Blox MSDS for you in our answer so that you may print them out and provide them to your vet.

The federal government has decided that certain types of rodenticides should not be sold in the same manner they have been after June 4, 2011.  These regulations were passed to try to prevent over the counter sales of rodenticides to homeowners and minimize secondary poisoning and misuse of rodenticides.  Unfortunately too many people have placed rodenticides in locations they should not be, such as easy to access places that children and pets can easily get to.  Basically all of the smaller quantities of rodent bait that you have been able to purchase over the counter will no longer be available.  You will only be able to purchase bait already inside a rodent station that is a one time use product.  It will come pre-baited in a sealed rodent station.  This will be the general rule for big box stores like Wal-Mart and Home Depot.  For a specialty store like ourselves, Do My Own Pest Control, we will no longer be able to sell certain rodent place packs, liquid rodenticides, or bait blox in smaller quantities than 16 pounds.  This was passed to discourage homeowners from purchasing rodenticides since they have to now purchase them in large quantities.  Most homeowners do not need 16 lbs worth of place packs.  We will be able to continue to sell the current stock that we have of currently labeled product while supplies last.  However, after June 4th, once we sell out of our current stock and start receiving newly manufactured bait, we will no longer be able to sell it in less than 16lb increments.  There will be some baits that we can continue to sell in smaller quantities but they will be very few and only the ones that have a minimal secondary poisoning risk.

The manufacturers have released newly labeled product as of June 4, 2011.  However, we still have the old labeled product until we sell out.

The risk of secondary poisoning with Contrac Blox is very minimal. A mouse only consumes a very small amount of bait at a time and passes it very quickly only keeping a smaller amount in their liver until they succumb to the effects of the bait. A cat would have to actually eat 20-30 mice that have consumed the bait for it to have an effect. In most cases well fed domesticated animals will not actually eat a mouse or a rat that they come across. Instead they will play with it, chew it and then leave it behind.

Contrac bait will not have any effect on insects. We recommend that you sprinkle a slug bait around the exterior of the bait stations to control the slugs before they enter the stations. We have several slug baits available including Hi Yield Snail and Slug Bait, Sluggo Plus Snail & Slug Killer and MotherEarth Granular Scatter Bait.

Unfortunately there is no way to stop the mice from going inside the house to die after they eat a mouse bait product. If having the mice enter your home after consuming the bait is an issue for you, consider using mouse glue traps placed in a Multi-catch Tin Cat mouse trap  or Mini T Rex Snap traps concealed in a Protecta Mouse Bait Station. This way you will know for sure where the mouse died and you can dispose of the carcass.

After a rodent consumes a lethal dose of the Contrac Blox it can take about a week for the rodent to die. You should keep replacing the bait until you do not have any more activity at the bait station because you could have more rodents than you realize, as is often the case.

Unfortunately the "special poison bait that will stop decaying rodents from smelling" is a myth. No known rodenticide will have this affect.  While there are odor control products that will help eliminate the odors resulting from decaying rodents, there are none known poison baits that prevent such odors. Please take a few moments to read our article Myths About Rodents to help sort out rodent myths and facts. The only way to avoid having an odor indoors is to use snap traps and glue boards so you will know exactly where the rodent has died and you will be able to remove the carcass.