Zoo Knoxville welcomed some new additions to its reptile collection Wednesday morning.

Heather Debord, a zookeeper in the department of herpetology, said caretakers were surprised to find four critically endangered Chinese Crocodile Lizards had been born. There are fewer than 1,000 of them left in the wild, she said. 

"We never know. Rarely would you see breeding activity, so we just get little surprises sometimes," Debord said. "It's kind of nice." 

The new babies come less than a month after caretakers discovered more than 30 reptiles, some critically endangered, died in one building at Zoo Knoxville. 

Debord said the zoo still boasts one of the top 10 collections of reptiles in the U.S., but the loss hurts larger conservation efforts. 

Zoo officials are still trying to understand what caused the deaths of several snakes and lizards. The building that housed the reptiles that died is still closed. 

MORE: Zoo Knoxville still looking for answers in death of 32 reptiles

"We are just trying to problem solve and trouble shoot, which is hard when we don't have answers," Debord said. 

The zoo has checked alarms and smoke detectors, but they are waiting for answers before deciding whether to reopen the reptile building that has been closed. 

In the meantime visitors can still view reptiles in the collection in other buildings. Debord said only about 15 percent of the zoo's collection is placed on exhibit. 

"It was nice to see that they still had snakes," said Rachael Dickerson, who came to the zoo with her family. "It was nice to see that they still had some for the kids to see and enjoy." 

The zoo continues to ensure that there will be more reptiles for visitors to enjoy in the future through its Species Survival Plan (SSP). 

Debord described it in simple terms as something similar to a dating service, matching animals together in hopes that they will reproduce. 

The lizards born Wednesday are part of the SSP, and after the deaths in the reptile collection last month, the births were a welcome surprise. 

"After such a heavy loss, we love our moments of joy," Debord said.