Taipei Zoo

Pangolins live in a wide variety of habitats ranging from foothills to mountains at 2000 meters high. These species, in particular, prefer secondary, broad-leaved forests at an altitude of 300 to 500 meters.
Pangolins are nocturnal burrowing animals. They generally reside on well-drained and thick layers of soil on mountain ridges. Their forelimbs and claws are well adapted for digging burrows for shelter and foraging. Burrow depth is measured as much as 5 meters in depth. 
 
The ground is uneven and bumpy in the pangolin exhibit because zookeepers mimic their habitats by creating thick soils to encourage pangolins to perform their instincts, including burrowing. The holes in the ground, hence, are dug by these  interior designers. It’s not that we neglected to tidy up.