Flight attendants have witnessed babies poo in the aisles and couples have oral sex on aeroplanes.
Areoplane
Staff have shared their bizarre sightings on Quora in a bid to share with the world many of the things they witness travellers do on a daily basis and still manage to cause shock.
One recalled seeing a mother let her child foul in the aisle, a couple giving each other mouth sex in their seats and a parent putting their baby in the overhead cabin.
Former flight attendant Heather Wilde said: ''People change their babies on the snack trays in full view of everyone like it is perfectly normal behaviour. Others decide it is too risky to use the lavatory to join the mile high club and just ask for a pillow - then leave it on the seat when they leave (which then goes straight into the trash).''
And air hostess Olivia Roqua recalled a hair-raising experience.
She said: ''One lady handed me a teacup to clear, then asked me to wait while she pulled some long loose strands of hair from her head, balled them up and popped them in the teacup that was now on my tray.
''I've also seen a woman put her baby in the hat rack and had people ask where the toilet is for US passport holders.''