On Thursday, an Air India flight from Delhi to Newark was forced to return mid-flight when the pilot reported a bat onboard to Air Traffic Control (ATC).

The Air India flight took off at 2:20 a.m. from Delhi’s Indira Gandhi International Airport (IGI), but the bat was discovered onboard after approximately half an hour in the air. After that, the flight captain opted to return the plane to its intended destination.

“AI-105 DEL-EWR returned to Delhi after departure after this local standby emergency was declared. On arrival, it was learnt that crew members saw a bat inside the cabin. Wildlife staff were called to catch and take away the bat. The aircraft landed safely at around 3:55 am, and later it was declared Aircraft on Grounded (AoG),” news agency ANI quoted DGCA officials as saying

The officials also reported that the aeroplane had been fumigated and that the bat carcass had been recovered.

“Air India B777-300ER aircraft VT-ALM operating Flight AI – 105 (Delhi- Newark) was involved in air-turn-back due to bat reported in the cabin by cabin crew after departure. Fuel was jettisoned and the aircraft landed safely at Delhi. After landing fumigation was carried out and a dead bat carcass was retrieved from seat 8DEF area,” a senior DGCA official said.

According to the article, the airline’s flight safety department will conduct a thorough investigation. In its original assessment, the Air India technical team indicated that unwelcome animals were brought in by third parties.

“The probable reason/cause may be loading vehicles like those for catering because all the time rats/bats come from their vehicle only,” an Air India official said.

The passengers were shifted to another plane–Air India flight AI-105– which landed in Newark at 11:35 am local time, the report said.