Very interesting. Thank you all for your suggestions and ideas. I thought there was something specific in a handbook I missed somewhere which explained the meanings of the thought bubbles. I'm glad to know there's not, and it's just us all trying to figure it out, lol. It's still frustrating at times, especially when I am unable to make out the object inside the bubble.
@DivinylsFan
The compost bin isn't an option because that's not available in my game, so I have to pick the bin up and put the trash back in it if I don't want vermin coming around.