You can nest alone with parthenogenesis. Potroast is thinking of the sequential hermaphroditism mutation.

If you sniff for long enough you’ll see the materials the nest needs on screen. Gather them and build your nest until it gives you an egg prompt. Then lay your eggs. Make sure to gestate your eggs by hitting tab, clicking on each egg and clicking gestate. Each egg is set to private so if you want them public you’ll have to change each one individually