It is possible to even sex newborns, but excellent eyesight isnecessary
For very young rabbits, the distance between the genitals and the rectum is the easiest way to tell. Does connect very closely, where bucks have a littlemore of a space.
For the older kits, scissor the tail between your first and second fingers and gently
press in front of the genitalia to expose it. Does will have a slanted "taco" appearance, where baby bucks will have a tiny protruding round"donut".
Since it is very easy to bruise and damage the genitals, do take care in attempting to sex them at a young age.
Occasionally kitsare mis-sexed even by the experts, so there's no way to be 100% certain, even with olderkits. Bucks with split penis (hypospadias) often appear to be does even up to 4 months of age. (The reason it is helpful to also observe the spacing between the genitals and rectum).