Mine never do 
Neither do mine, they never have and they're 8,6 and almost 4. Occasionally when Tilly has an IBD flare up and a really bad stomach she'll stand and stare at me and she's desperate to go but that's the only time. As they get older they get a routine so you'll know when they usually go without them having to ask, other than last thing at night mine mostly go when we're out on their walks.
