New Delhi, India – Indian officials have floated a controversial plan to introduce apex predators such as crocodiles and venomous snakes into riverine stretches along the Bangladesh border, to act as natural deterrents against undocumented migration and smuggling in places where erecting fencing is difficult.

India’s 4,096km-long (2,545-mile) border with Bangladesh runs through some challenging terrain – and New Delhi has found some stretches impossible to fence.

In an internal communication dated March 26, India’s Border Security Force (BSF), which patrols international borders with Pakistan and Bangladesh, ordered personnel at its headquarters on the eastern and northeastern fronts to explore “the feasibility of deploying reptiles in vulnerable riverine gaps”.

The government’s latest move to fence the border with Bangladesh has alarmed human rights activists and wildlife conservationists alike in India.

What are the risks of such a move for local communities on both sides of the border – and for the ecosystem of the region?

Why does India’s border force want to deploy killer wildlife?

The India-Bangladesh border runs along the Indian states of West Bengal, Tripura, Assam, Meghalaya and Mizoram. There is difficult and unforgiving terrain in these areas, passing through hills, rivers and valleys.

New Delhi has fenced nearly 3,000km of the border. But the remaining stretches include marshy and riverine areas with local populations living on either side.

In its recent communication, the BSF directed its frontier units to observe “strict compliance” by “exploring use of reptiles in riverine gaps”. The officials were also instructed to share “action taken” after receiving the direction. This was first reported by Northeast News, a regional publication.

The Ministry of Home Affairs noted in its report last year that, despite the punishing terrain, the BSF has diligently performed its duty to curb illegal cross-border activities and undocumented migration from Bangladesh.

That report also noted: “Some problem areas such as riverine/low-lying areas, habitations close to the border, pending land acquisition cases and protests by the border population, have slowed down the installation of fencing in certain stretches on this border.”

Analysts and activists have expressed alarm at the prospect of dangerous animals such as crocodiles being used to deter refugees and migrants.

“This would be hilarious if it weren’t sinister and dangerous,” said Angshuman Choudhury, a researcher with a focus on northeastern and eastern Indian border states. “It’s absurd, right?”

Looking at it objectively, argued Choudhury, “once you release venomous snakes and crocodiles, they won’t be able to differentiate if it’s a Bangladeshi or Indian”.

“This is peak cruelty against and dehumanisation of undocumented immigrants. A whole new way of weaponising nature and animals against human beings.
It’s biopolitical violence of a new kind.”

“It is the Achilles’ heel in the India-Bangladesh border: the river,” he told Al Jazeera. “This core impulse comes from the fact that the BSF has always found that the river on the border is practically impossible to fence.”

What’s behind this idea?

India’s Hindu majoritarian government, led by Prime Minister Narendra Modi, has long argued that undocumented migrants are a threat because they change the demographics of India.

Human rights observers say Modi’s government has used this rhetoric to harass religious minorities in India, especially Bengali Muslims in the eastern and northeastern parts of the country.

The partition of British India in 1947 sliced through the region of Bengal, with people on either side of the border still sharing cultural and ethnic roots.

BSF officials have, on several occasions, made headlines for physically pushing Indian Muslims into Bangladesh at gunpoint.

There are no formal statistics on the number of undocumented migrants in India. While a new census was begun this month, the last one was undertaken in 2011.

Even if the number of undocumented migrants is rising, said Harsh Mander, a human rights activist, rather than engaging with Bangladesh’s government and following the judicial process to hand over undocumented immigrants, India has opted for “extrajudicial methods” to deal with them.

Furthermore, activists say India is using this as an excuse to mete out unfair treatment to minorities, especially Muslims, by conflating them with migrants.

“India’s approach on the question of what they call ‘contested citizenship’ is one of both cruelty and the defiance of the constitution and international principles,” Mander told Al Jazeera, referring to the government’s drive to round up migrants but, in reality, pushing Indian Muslims across the border and labelling them Bangladeshi.

“This [targeting Muslim Indians] is also a way of continuously keeping Bengali Muslims in the sense of ongoing dread that they might be stripped of citizenship and rendered stateless,” Mander added.

In the state of Assam, for example, Choudhury said, India set up foreign tribunal courts – quasi-judicial bodies established to determine whether a person suspected of being an illegal migrant is a “foreigner” or an Indian citizen under the Foreigners Act of 1946.

Choudhury said he has worked on many cases of Indians being declared “foreigners” in Assam and West Bengal “just because they couldn’t produce documents [that proved their citizenship]”.

“These forced expulsions are new border control mechanisms, which are very sinister,” Choudhury said.

The notion of introducing crocodiles and venomous snakes into border areas is an extension of the same policy towards Indian Muslims, he said.

How will crocodiles and poisonous snakes affect the local ecosystem?

Crocodiles are not native to the riverine stretches along the India-Bangladesh border, Rathin Barman, chief of strategy and liaison at the Wildlife Trust of India, told Al Jazeera.

A species of crocodile is found in the Sundarbans, in southern West Bengal, and another in the restricted wetlands of Assam, far from the border areas. If they are moved to the border areas, they may not survive, Barman said.

“First thing you know, they end up dead soon,” he said. “The same goes for so-called venomous snakes.”

Barman warned against “any manipulation to the natural distribution range of species”.

“If we do impose [this], it may intervene in the entire chain or ecosystem,” Barman said. “I am concerned about other creatures who have equal rights to live in this world and in those stretches.

“Technically, it is definitely not advisable,” he added. “It will definitely never work in an open, flowing river.”

The swampy stretches along the India-Bangladesh border are also prone to flooding, which could result in poisonous snakes spreading into residential areas, exposing the local communities, particularly those involved in fishing, to grave risk.

“This kind of policy reflects the Indian state’s cruelty,” said Mander, the human rights activist. “There’s no reason to expose an undocumented immigrant in a river to crocodiles and snakes, or the threat of gunpoint.”

“These animals cannot do what the Indian state is unable to: to identify who is an ‘illegal infiltrator’,” he added. “They will, of course, attack the local population on either side.”

Has this been done anywhere else in the world?

There is no modern precedent for deploying natural predators to fence an international border.

United States President Donald Trump was reported to have discussed ideas to deter migrants during his first presidency, including building a moat filled with snakes or alligators, and shooting people in the legs.

He denied the reports, saying, “I may be tough on Border Security, but not that tough,” and called it “Fake News!”

However, a comparison of sorts has arisen in the US. The South Florida Detention Facility opened to controversy in July 2025 and has been dubbed “Alligator Alcatraz” by state officials, who support Trump.

The place got its nickname for its remote, swamp-like location, where the terrain, believed to host predators, acts as a perimeter that makes escape impossible. The centre has become notorious for inhumane conditions and has faced criticism for harming the fragile Everglades ecosystem, noted Amnesty International, which has called for it to be shut down.