Visitors pose for photos with Halloween decorations at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

Visitors wearing costumes take part in a Halloween activity at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

A red panda plays with a pumpkin at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

Visitors pose for photos in front of a Halloween decoration at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

Visitors pose for photos in front of a Halloween decoration at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

Visitors wearing costumes take part in a Halloween activity at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

Lemurs play with a pumpkin at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)

A child poses for photos in front of a Halloween decoration at Pairi Daiza zoo in Brugelette, Belgium, Oct. 31, 2019. A series of activities were held at the zoo to celebrate the Halloween, attracting numbers of locals and tourists. (Xinhua/Zhang Cheng)