How do you sex rabbits?
An un-neutered, mature male rabbit, (several months old and
more), will have two large pink testicles under his belly near the
back legs. A female will not.
In younger rabbits, it is harder to tell. Grab the rabbit and
turn it on its back in your lap. It helps to have someone to hold
it while you check. Hold the tail back and press gently either side
of the "area in question" (you're looking for the slit-like, pointy
hole here, not the bit where the droppings come from), so
that it sort of rolls outwards. There is a knack to this. A female
will come out to be a pyramidal shape with a slit up one side, a
male will be straight up-and-down like a post and with a round hole
in the middle. Also if the male is more than 3 or 4 months old you
may see a rounded protrusion appear in the middle.
Sound hard in writing, but once you've seen both it is easy to
see the difference.