Rats have known to cause a menace to the human population since medieval times. The bubonic plague, of which rats were the primary organisms of transmission and propagation, leading to the death of tens and millions of humans in the 1300s. Not only the plague, but rats are also infamous for the transmission and sustenance of other lethal diseases such as typhus fever since their body houses the causative agents for these illnesses.
Rats can contaminate food and beverages with their hair, urine, and fecal droppings thus resulting in the spoilage of food products and severe food poisoning if humans or other animals happen to consume such contaminated goods.
Rats are highly adaptable towards a variety of environments because they can feed on almost anything from food scrapings to insulations around wires which can lead to short circuit thus increasing the risk of fires. Rats spare nothing; they will gnaw into any item they come across thus causing damage to important documents, clothes and other valuable house items. The presence of rats also generates foul odors in the house.
The elimination of these pesky rodents is therefore extremely necessary to prevent all the above-mentioned conditions. One of the most commonly employed techniques for getting rid of rats is the use of rat poison, which comes under the nonspecific pesticides known as rodenticides.
Different rodenticides have different modes of action, some of them are anticoagulants i.e. they inhibit normal blood clotting processes in the body and cause internal bleeding (such as Warfarin and Bromadiolone), some of them destroy the nerve cells leading to paralysis and death (such as Bromethalin) while others induce toxicity in the body which results in death due to heart, kidney, and gut failure (example includes Cholecalciferol). Due to these varying modes of toxicity, these poisons are classified as a single dose and multiple doses, depending upon the number of doses required to cause significant lethal toxic reactions.
Since these poisons are nonspecific, they have similar toxic effects in the human or animal body as in the rodents, therefore, they are to be used with great care and appropriate precautions must be taken.
Using rat poison is an effective method to get rid of the rodent nuisance however their nonspecific nature puts human and animal life at an equal risk of toxicity resulting from these chemical agents. Thus great care and preventive measures must be observed while using rat poison within the home environment.
Following are a few important considerations to be kept in mind while using these chemicals:
- The specificity of action:
Selection of poisons which don’t harm humans or other non-target animals such as pets is of primary importance. Following is a list of poisons that can be used while protecting yourself and others from the lethal side effects:
- Bait stations:
A bait station is a tamper-proof apparatus which prevents children and pets from coming in contact with the poison. They have a small opening which allows the entrance of rats. Bait stations with an increased efficacy come with the poison already installed within the device so that you don’t have to come directly in contact with it reducing the risk of skin irritation.
Depending upon the severity of rat infestation, you can place a number of bait stations in areas where an increased rat population is observed. They can be left in an area for as long as two weeks. Check them every morning and dispose of the stations whose apparatus has been damaged resulting in the exposure of the bait. They are especially effective for use in outside areas.
- Poisons safe for nontarget species:
While most of the rat poisons are toxic chemicals causing an equal amount of damage to other living organisms, some poisons are made up of nontoxic agents like gluten and salt, which cause dehydration upon entering into the rodent body, inhibiting the uptake of water ultimately killing the rat.
Such poisons are nontoxic to pets and children, and can also be safely used near livestock feed. These poisons are also safe for the scavengers which hunt and consume the dead rats.
- Metal phosphides:
Metal phosphide-based poisons when ingested by rats, release a toxic mustard gas called Phosgene which kills them. After killing the target species the gas dissipates, thus rendering the rat corpses nonpoisonous for the predators which feed upon them.
However, the poison itself is still very harmful to humans, therefore, it must be used in restricted areas inaccessible to nontarget organisms.
- Removing food and beverages from the infested area:
It is ideal to remove all the possible items upon which rats feed such as food products, animal waste, cereals, etc. so that the rats are left with no other option than to eat the poisoned bait.
- Training the rats:
Rats don’t have the ability to vomit, therefore it is an inbuilt trait of them to first sample the food item before fully consuming it. The rats firstly consume a small portion of the new food item and then wait for the harmful effects if any. If they happen to experience some discomfort or side effect they will not eat that item anymore.
In order to prevent this, the rats must be trained so that they will ultimately consume the poisoned bait. For this purpose, the bait should be free from the poison for the first three to four days so that the rats become accustomed to it. Once this aim is accomplished, poison the bait the rat has become accustomed to, remove the unfinished poisoned bait every morning and replace it with a new one. Repeat this process for about a week until all the rat population has been completely eliminated.
- Avoiding moisture:
Placing the poisoned bait in an area with high humidity or moisture can disrupt the chemical linkages inside the poison thus rendering the poison ineffective or significantly reducing its efficacy. Avoid placing it in damp areas or areas with high-temperature extremes since mice prefer cooler places. Elevated temperature also leads to a reduction in poison efficacy.
- Bait variety:
Sometimes rats don’t eat a certain type of food due to various reasons. You need to experiment upon this by using different types of food items as bait until the rat chooses its favorite one.
Rats have a well developed nervous system and are thus intelligent creatures. They are sensitive towards the continuously changing locations of the bait and will discontinue consuming the item they find suspicious, thus great care is to be taken in this regard.
- Identifying rat infested areas:
Baits will obviously work best when placed in a rat-infested area or areas where there is a significant rat population. Thus identifying such regions is of key importance for successful elimination of these pesky rodents.
You can identify rat infested areas with the help of the following features:
- Holes and burrows:
It is common for rats to excavate burrows or dig holes for them to stay in or store food. These holes can be found near heaps of animal waste and food items.
- Grease marks:
Rats often use similar tracks to move in and out of the house. Rats being dirty infested creatures leave behind dirt marks and greasy streaks along the paths they travel which can be easily identified.
- Fecal droppings:
Rats are known to produce about forty droppings every night, which are dark in color and have the appearance of a rice grain. They are about nine to ten millimeters in length having a foul odor.
- Bite marks:
Rats have a habit of gnawing on most of the items they come across even the non-edible ones like plastics and cables in order to stop their teeth from growing, which is a typical characteristic of all rodents. This gnawing activity leaves behind bite marks on the items that have been chewed.
- Tail marks:
Tail marks are evident in dusty areas from where the rats pass. You can also purposefully dust an area in order to detect the presence of these rodents.
- Proper disposal of the corpses:
Rat corpses are still a potential health hazard since their body harvests a significant number of bacteria and pathogens. Also, unattended corpses generate an extremely foul smell. Therefore dead rats should be properly disposed of using gloves and plastic bags as soon as possible. Don’t forget to thoroughly disinfect the area where the rat died.
When rodent bait is used on a regular basis it is recommended that baits should be rotated every couple months or so.
In some cases, rats will ignore your bait so it helps to try different baits. In some cases, rats may become resistant to the bait being offered.
In most cases, using any bait available will do the trick. However, it is critical that whatever bait you choose is protected from children and other, non-target animals.
If you are keeping bait out consistently, it is always recommended that baits be rotated. Of course, practicing IPM (Integrated Pest Management) is a fancy way of saying, clean up any areas and seal any entrances as to not make the areas conducive to rodents.