The phrase "nest mates" refers to animals that live in the same nest or habitat. They are usually siblings or members of the same family. Full definition
If you are new to Internet dating or haven't been on a lot of dates in the past year, then aim for dates and not your mate in your dating profile. (datingadvice.com)
Elephants don't mate with oak trees to produce really big acorns. (sciencenews.org)
The genetic analysis shows that there are four highly distinct groups of giraffe, which apparently do not mate with each other in the wild. (sciencedaily.com)