Got sucked into reading the DL CoCs (there's a domestica and international one), here's a fun fact. Page 13 of 58 in the domestic states:

2) Accompanied Children Less Than 2 Years Old.
One child less than 2 years old not occupying a seat may travel with an adult fare-paying passenger at least 18 years old or parent/legal guardian at no additional charge. Additional infants and infants occupying a seat must pay the applicable fare. A maximum of 2 infants is permitted for each adult. Delta recommends the child be placed in an approved safety seat.

Yes this isn't called out in the international CoC (or at least can't find it yet).

So if you can handle 2 infants and 10 children domestically... more power to you.