I had to move the cats' litter box out of the bathroom when I started brooding chicks in there. Didn't stop them from wanting to come in and visit with me. Plus the dogs always wanted in there any time I went into the bathroom. The door has been continually closed and their access denied since I started incubating and brooding chicks, last Summer.
However, the two dogs whine outside the door, sometimes pawing at it, when they think I have spent too much time in there without them. And the cat will push their paws under the door and meow.
Now that I have three older chicks who have been getting out of their brooder and investigating the bathroom, there have been some hysterically funny moments with a cat's paw getting pecked - purely out of chicken curiosity. And a chicken bending down to peer through the gap under the door whilst a dachshund is snorfling at the same gap, oh, that is priceless!