Ants in Cambodia are omnipresent. 24 hours per day they search for eatables everywhere. They specifically love any meat products and sweet food like cookies, sugar, sweet tea or coffee. They even drink the rest of wine from your glass. If you forget a ham sandwich on your table, 15 minutes later it will be totally covered by a thick layer of ants. Pack all food in plastic bags or keep it in the fridge – ants never visit fridges, they don’t stand low temperatures; they die in the fridge in minutes.
Any Khmer house or hotel room has generally two or three old-resident ant families. You may try to use repellents, it helps a couple of days but afterwards ants will come back without fail.