The U.S. Department of Transportation is looking to crack down on emotional support animals on flights.

The practice of bringing non-service-trained animals onto commercial flights has become an embattled topic. The DOT announced Wednesday it is seeking public input on proposed changes to current rules.

Under current policies, travelers are allowed to fly with pets, which include everything from hamsters to reptiles. The rules would, among other changes, allow carriers to limit the number of service animals per person, to just two.

According to Gizmodo, the rules would also require the animal to fit in the space between the owner’s feet on the aircraft. The public now has 60 days to comment on the proposed changes.