While Americans were left in awe by the solar eclipse on Monday, animals were alarmed. Video footage shows giraffes, zebras and ostriches running around in circles as total darkness fell over the zoo on April 8.

The historic day for Dallas, which will not be seen in the path of totality for almost 300 years, was last seen in 1878. Although there was a lot of excitement surrounding the eclipse, there were concerns about traffic jams and fuel shortages.

As the sky went dark, the animals were seen running to their indoor habitats while birds headed to their evening nests and suddenly grew quiet.

According to reports, Chimpanzees patrolled the outer edge of their habitat at the zoo while all but one of a bachelor group of gorillas went to the door they used to go in at night.

Although solar eclipses don’t happen so frequently, researchers don’t know much about how they impact animals.

“We never know how our animals are going to react because they are wild,” Ann Knutson, a zoological manager of birds at the Dallas Zoo, said.

The Dallas Zoo is where more than 4,000 people gathered to watch the total solar eclipse. The Zoo offered a special eclipse event with staff stationed around the park to discuss how the animals reacted.

Ahead of the eclipse, Christine Montgomery, Manager of Applied Behavior, expressed her excitement for what the animals will do.

“This is the first eclipse that we’ve had here in the Dallas Zoo, so we are interested to see what our animals are going to do,” Montgomery said. “We’re not anticipating them doing anything remarkable, but come along to the zoo with us. We’re going to be observing and seeing what happens, so you’re going to learn right along with us.”

Montgomery also said primates might react, especially when the sun goes down, which usually signals dinner time. Birds might also react, thinking it’s time to perch for nighttime.