Just a week before the Maharashtra government’s circular to ban glue traps came into effect, a 1.5ft Indian rat snake in Thane was diligently performing its duty by keeping the local rodent population in check. Before it could prey upon the rat, it found itself stuck in a glue trap. A week before that, a parent sparrow lost its life to these deadly traps in Mumbai’s Ghatkopar, leaving its helpless babies orphaned.
In the last decade of volunteering with RAWW Mumbai, an organisation that rehabilitates distressed wildlife, I have witnessed hundreds of such cases. Species such as the Indian rock pythons, Indian spectacled cobras, monitor lizards, eagles etc. which have the highest level of protection under the Wildlife Protection Act of 1972, have repeatedly fallen victim to these deadly traps. Since 2020, more than 200 such cases have been recorded by the organisation. In addition to this, common animals and birds which do not have protection under the Act, like pigeons, bats, squirrels and frogs, often go unreported.
How is the rodent population controlled in Mumbai?
It is very important first to acknowledge that Maharashtra, particularly Mumbai, has been battling with the rodent menace for decades, which has led to the usage of such traps as ‘solutions’. In the last three years, the BMC has spent Rs 12 crores as payment to the ‘rat labourers’ who work during the day and contract workers during the night to kill these rodents. As of 2023, BMC pays Rs 23 for killing one rat and a set monthly target.
The rodents can be potential carriers of several infectious diseases. During monsoon, there is an increase in the cases of leptospirosis, an infectious bacterial disease that humans can contract when they come into contact with water or soil contaminated by the urine of infected animals like rats and dogs. In 2023, Maharashtra reported 1,283 cases of leptospirosis, of which Mumbai reported around 94.93 per cent of cases, as per this Mid-Day report.
The BMC follows a 4D strategy to eliminate rats. As per the pesticide department, hospitals and households can follow the four steps to prevent rat infestation. The first D (deny entry). Sealing off potential points of access or entry to prevent rat infiltration. The second D (deny shelter) means to ensure there are no hiding places where they can take refuge and breed. The third D (denying access to food sources) means proper food storage and waste management that will reduce their incentives for staying. And last D (destruction or elimination). This is a departmental intervention wherein rats are trapped, poison-baited, or the pesticide department of the BMC fumigates the area.
Challenges in implementing BMC’s 4Ds
The first three Ds are not one-day solutions. With the weight of the human population that the city is carrying, it is not surprising that these have not proved to be satisfactory or effective solutions. Mumbai has three different types of rodents: indoor rats, also known as the black rats, commonly found in households. Drain rats, also known as the brown rats commonly found in nallahs, sewers and outdoor rats that are commonly found in open spaces and big godowns.
Rats in metropolitan cities rely heavily on food waste. Garbage mismanagement is one of the major reasons for the dominant presence of rodents. According to BMC data, out of the total waste that Mumbai generates, 70% comprises food wastage. Even though segregating the dry and the wet waste at the source is mandatory, non-compliance by housing societies continues to pose a challenge.
When waste segregation fails and the menace of rat infestation increases, people resort to the fourth D, which on the face, appears a ‘quick’ and ‘safe’ solution. Many offices, hospitals and residential societies opt for different methods to eliminate the rats.
Irreparable damage to the wildlife
Three methods are commonly used to kill rats: glue traps, bait stations and poison. Glue pad adhesives have the potential to peel off human skin. When an animal is stuck onto a glue pad its immediate response is to escape, and hence it applies excessive pressure to free itself from the adhesive. Avian vet Dr Rina Dev who regularly helps wildlife NGOs in Mumbai address such cases, says in this PTI report, “If a bird gets stuck in a glue trap, its feathers and wings get damaged and this can result in permanent loss of its ability to fly.” Similarly, reptiles and mammals lose their skin and their internal organs are left exposed, which can lead to death if they are not provided timely medical attention, said Dr Priti Sathe who runs Himi’s Bark Veterinary Clinic, further in the report.
The bait stations are more dangerous for the native wildlife. Inside the rectangular wooden or plastic boxes, the glue pads are placed at the bottom along with the poisonous food that lures the rat. Even if the stuck wildlife manages to free itself from the glue, the bait station that is closed from all sides does not provide an exit. This animal continues to struggle for several hours and if help is not received in time, it ends up losing its life.
Long-term effects of rat poison
The third and cheapest way to kill rats is the use of rodenticides or rat poisons that are available in most online shopping portals and offline stores. They are considered to be an instant solution to eliminate rats. Several pest control agencies formulate their own, which are usually demanded by the housing societies and hospitals. The Navi Mumbai Municipal Corporation has eliminated 27,521 rats in the last four months using poison tablets.
Once the ‘cake’, a colloquial term used to refer to the poison, is consumed by the rat, it does not die instantly. Most companies mention on their product labels that the rats will die in one feed, however, within 4 hours to 4 days. This is done to avoid the handling risk that one may face while disposing off the dead rats.
The Anticoagulant Rodenticide (AR) is one of the most common lethal poisons that interfere with blood clotting and kill rats through haemorrhaging. When animals or birds of prey feed on such rats, they often end up consuming the harmful toxins.
There is neither enough data nor any specific research study in India that sheds light on the presence of AR in the bodies of prey birds and mammals. However, as early as 1999, a study conducted at the Institute of Terrestrial Ecology (ITE) in the UK showed an increase in anticoagulant rodenticide exposure in the bodies of predatory birds from 5% in 1983-84 to 36% in 1995-96.
Misuse of rat poison to kill human and wildlife
Many animals in India that become agricultural pests or are declared vermin are often killed through poisoning. In Himachal Pradesh since 2016 several farmers have admitted killing the macaques through poisoning to save their fields. In 2020, two macaques were found dead near Mallikarjuna temple in Bengaluru with rat poisoning suspected as the cause. In 2022, 15 peacocks died in Tamil Nadu after they consumed rice laced with rat poison.
Several news reports highlight the use of rat poison by individuals to die by suicide. In January 2023, a man from Aurangabad consumed rat poison and also made his twin kids consume the same, fortunately the kids survived, he died by suicide. In 2021, as many as 7,041 people died by suicide in Tamil Nadu after they consumed rat poison. This later led to a complete ban on its sale, purchase and manufacturing in the state.
NCRB’s data (Page 217) on Accidental Deaths and Suicides highlight the different means/modes used by people to die by suicide. As many as 41,197 people used poison to die by suicide in 2021. Although it is inclusive of all the other kinds of poisons like the pesticides, it brings forth the pressing need to regulate the easy availability of such poisons.
There are no overnight solutions
All these points bring us back to the question. Is there a one-point solution to curb the rat menace in Mumbai and the answer is: absolutely not. There are several ‘natural’ rat repellents available in the market but they do not guarantee regular effective results. Maharashtra is the 4th state this year to ban glue traps, but they are still available in both online and offline stores. The copy of the government circular is not easily available in the public domain and most people are unaware of the ban. At the same time, there is no regulation on the sale and purchase of rat poison. A single pack cost anywhere between Rs 12 to 40.
The Animal Welfare Board of India (AWBI) had issued guidelines regarding the use of glue traps and other methods that pose a threat to the native wildlife two decades ago. However, it is with the respective state governments to ensure effective implementation.
Impact of rat menace on human life is as important as the impact of glue traps and poison on wildlife. The solution to these two seemingly competing problems lie with the humans.
Most calls of wildlife being stuck in glue traps or poison bait stations are reported to RAWW from the residential areas. Animals are found in distressed conditions inside the human houses. Controlling the menace in large food godowns and hospitals may become difficult and they are left with no choice but resort to such methods. But, at an individual level we can improve the situation. Blocking the food sources and keeping our surroundings clean is all it takes to push them away without resorting to inhumane and ineffective methods.
Rats are here to stay as long as humans are destined to live on the earth. The earlier we accept this fact the better. What is important is to consider the rat like any other mammal. It is not just a rodent or a pest, it is both a prey and a predator in the food chain.
Rats have no affinity towards humans but they love spaces inhabited by us because of the mess we create (wherever we are and wherever we go). We are the biggest source of (junk) food for them and everybody loves free food, isn’t it? Only when the first three Ds rightfully proposed by BMC are followed at the level of individual lifestyle, we can tackle the menace. Until then the misuse of fourth D will continue to kill everyone except the rats.
This story has been written as part of the My City Writers’ Training Program.