Unless there’s an obvious trail leading too/from the den, I’d think ambush hunting them would be tough. I’d be tempted to set up downwind of the den and use a very quiet call. Like vole squeeks or a wounded bird. And I’d be ready for multiple coyotes to come in.
If that didn’t work, I’d assume “nobody home” for now and come back and try it again in a few days or something. Personally, I’d want to stay well away from the den to minimize risk of either sound or scent ruining the whole deal and driving them away.
I personally don’t think it’s unsporting at this time of year when last year’s pups are grown and able to fend for themselves. I’m not sure I’d be keen on working an active den if there were young pups in the den. Just to be clear, I’m not saying it’s unethical because obviously if there’s a situation where the coyotes are preying on livestock, or what have you, it may be justified. But just for sport hunting I’m of the opinion that during the time when the pups are in the den and dependent on the mother, I’d leave them alone.
Grouse