What do pilots do, when there is a long wait before take-off, after gates are closed? Pilots are supposed to carry out the mandatory checks before the flight take-off or taxi. But what happens when there is a delay, when the aircraft cannot push back from the gate, due to non-clearance from ATC, or due to heavy traffic etc.

Do the pilots, re-run the checks, or carry out more extensive checks of the aircraft?
Do the pilots just chit-chat, eat, or make phone calls to their family?
Is there any standard procedure to be followed during this wait time?


Edit: As someone tagged this as duplicate, my question no where suggests time spent by pilots during long haul flight, its about what they do when the pushback is delayed. Hope it helps.
Apart from what Daniel listed already, they're also nervously watching the clock.
If they're late by too much they may miss their mandatory crew rest period and have to cancel the flight or hand over to another crew.

This can of course get very expensive for the airline, especially if all or most passengers have to be accommodated in hotels overnight for a departure the next day in case no replacement crew can be arranged or the forced delay causes the flight to be unable to take off due to closing of the departure airport before departure or closing of the destination airport before arrival there.