Elephants’ intense fear of bees may just save their lives.

One of the most common causes of death for Asian elephants in India isn’t poaching (due largely to their smaller tusk size), but train accidents.

From 1987 through July 2017, 266 elephants have been hit by engines in the second most populous country in the world. So far in 2018, 15 elephants were killed on the tracks. Experts think the numbers could be due to more trains, faster trains and/or a burgeoning elephant population, but measures such as warnings and reduced train speeds haven’t necessarily made a measurable impact on mitigating deaths.

Enter bees.

Despite their thick skin, both Asian and African elephants are so terrified of bee stings that the vast majority will turn to run “within seconds of hearing the sound of buzzing,” scientists explain. No one is yet exactly sure why that is the case, but organizations in elephant-populated areas have been experimenting for years with using bees and bee sounds to repel pachyderms.

The Forest Department in India has been using drones that emit buzzing-bee sounds to scare elephants away from neighborhoods, farmland and areas known to be frequented by poachers, and farmers in Africa have installed beehives to keep the elephants from eating their crops. African elephants are reportedly even more afraid of bees than Asian elephants; experts surmise this could be because bees in Asia are less aggressive than those in Africa.

Late last year, rail officials in eastern India began installing devices alongside the train tracks that emit bee sounds downloaded from the internet, and it seems to be working: This year only six elephants have died from train accidents in the immediate area, compared with 10 at this time in 2017.

“We installed this in Rangiya division, and once it was successful we have installed it in other locations as well. This was started barely six months back,” Lokesh Narayan, additional general manager of Northeast Frontier Railway, toldThe Times of India.

India’s train system, which dates back to colonial times, covers more than 41,000 miles. In the early 1990s it was converted from meter gauge to broad gauge, which allowed for increased train speeds through 20 of India’s 101 known elephant corridors — a deadly combination.

“You can look at it as a demographer or from an emotional viewpoint,” Raman Sukumar, an elephant ecologist at the Indian Institute of Science, told National Geographic. “Train accidents don't make much difference in population. That's a very dispassionate view. But look at the mascot of Indian Railways. It's an elephant. The Railways cannot be killing their own mascot.”

The question remains among scientists, however,  why elephants — which feature the largest brain of any land animal and three times the number of neurons as humans — would not move out of the way of an oncoming train. Most of the accidents happen at night, so it could be that the animals are blinded by the light and/or confused by the noise.

“It’s highly unlikely that they would get stuck in the tracks,” Sukumar told National Geographic. “It’s puzzling why this highly intelligent animal would wait on the tracks when it can even feel the vibration of the train’s movement.”