Popcorn boxes, empty bottles and potato chip wrappers are all in a day's work for cinema cleaners.
But they have also unearthed puzzling items from under the seats of movie theatres, such as soiled baby diapers and even live crabs.
The mess made by moviegoers after a screening can be challenging to clear up, but cinema operators are now seeing a silver lining.
Recent efforts to urge patrons to clear their trash on their way out after a movie are starting to pay off, they told The Sunday Times.
While they do not track the amount of rubbish collected, cinema chains such as Golden Village (GV) and Shaw said they are noticing more patrons chipping in to help keep their venues clean.
As a result, GV, which runs 12 cinemas here, said the number of man-hours put in by its cleaners has been reduced.
Shaw, which operates seven cinemas, is also seeing more people clearing up their trash after each screening.
Mr Terence Heng, vice-president for innovation, content and engagement at Shaw Organisation, said such civic-minded patrons help make cinemas more pleasant for others.
This comes after a string of initiatives, such as in-cinema visual reminders, to rally moviegoers to clear their trash.
For instance, a video series featuring two friends with different views on kindness has been screened before the start of movies by some operators since June. It addresses issues encountered by moviegoers, such as littering and the use of mobile phones during screenings.
The bulk of the trash is packaging from snacks and drinks sold at the cinemas, such as popcorn boxes and nacho trays. Also common are potato chip wrappers and drink cartons. Some eyebrow-raising items include luggage, prams and even a bag of new underwear. Wallets, keys and coins are also sometimes left behind.
These items are usually kept for a period. If nobody claims them, they are either discarded or donated to charity. Consumables are kept for 24 hours before they are thrown away. This was the case for the live crabs that were found at GV Jurong Point a few years ago.
Mr Kelvin Gay, a business relationship manager at Jusclean Services, the cleaning contractor for GV Paya Lebar, said some inconsiderate habits remain. "There are some people who slot wrappers in between the seats. Others would wipe their dirty hands on curtains."
He added that cleaning up is often not easy as popcorn and food scraps can end up stuck between the seats.
Typically, a cleanup is done after each screening. The lights are switched on and cleaners - armed with vacuum cleaners, wiping cloth and disinfectants - spend 10 to 20 minutes tidying up the cinema halls before the next movie comes on. They remove litter on the carpet, perform a wipe-down of the seats and attend to any spillage, among other tasks.
Staff from the cinemas also work alongside them, checking under the seats for forgotten belongings.
After the last show at the end of the day, a more thorough cleaning of every hall takes place. The intensive nightly cleanup, which includes vacuuming between the seats, takes about an hour for each hall.
When The Sunday Times visited GV Paya Lebar last Wednesday night, a comprehensive cleaning process was under way. Trash such as nacho trays, sweet wrappers and food containers was lying around. One cleaner, armed with a heavy-duty vacuum cleaner, was cleaning the seats and carpeted floor, while another picked up rubbish and wiped cup holders with disinfectant.
While moviegoers are increasingly cleaning up after themselves, cinemas believe more can adopt the habit.
Ms Mable Gan, GV Paya Lebar's assistant cinema manager, said: "It is a good habit to practise anywhere, not just in the cinemas."