Why not reciprocate.
With the ongoing food rationing around the world, the last thing we hope for is to have an additional food consumer in the house. Hence, If they eat your food try to get your ration back by eating them as (t_coffee_me suggests chilly fry).

Same thing when a fly gets into your drink, take the fly and squeeze the drink out of its system, then drink it. In that case, you have got back your drink (plus extra) and may be a good lesson to others that are hoping to do the same!