When Digit the gorilla's biological mother refused to breastfeed her, the Thivillons decided to take her in. Apparently French zoo animals are just one formula meal away from being adopted by locals.
"Good to know!" – Bilingual French elephant
Now, I know what you're thinking: that gorilla is definitely going to end up murdering them. But we can't live our lives not doing things simply because those things may kill us. Would you not jump off a building just because MAYBE the fall would break your neck? Exactly.