Quillby and Maude, two adult porcupines from a breeding facility in Pennsylvania, have joined the National Zoo to potentially make more porcupines.

The 10-year-old porcupines are on exhibit next to the prairie dogs, according to the Zoo. The two long ago reached sexual maturity, which means “it is possible that Quillby and Maude could breed and produce offspring.” From the Zoo:

The North American porcupine is one of the largest rodents found in North America, coming second to the North America beaver. Their fur ranges in color from brownish-yellow to black, and they sport white highlights in their quills. They weigh 20-30 pounds and are 2¬-3 feet in length. North American porcupines are native to the coniferous and mixed-forest habitats of Canada, the northeastern and western regions of the United States and northern Mexico.

Good information, National Zoo, but how do they — breed? A 2012 Slate piece on porcupine sex explains that involves persuasion, climbing trees and urine.