Mind your manner please?

A friend of mine from another lab wrote this in FB just an hour ago --->"UG nwadays seem more powerful than master, one UG ask r u going to open prep room sunday? i said no, she ask then hw is she going to read the OD? she throw the qs to me wan me figure out hw. y she din even plan her work and make sure the lab is open b4 she start her work??"
Looks like I'm not the only one facing such problem. Just yesterday I had a very 'funny' encounter with an undergrad from another lab. She came into our lab to visualize he gel under UV light and asked if I'd be staying back a bit late. I said 'ya' and then she told me that she needed to go upstairs to get her camera and came back down to take a picture of the gel etc. I mean I don't mind waiting a bit but the way she talked to me is like I'm her subordinate, not to say rude but it's like ordering me. " Gel saya masih atas UV itu tau? Jangan buang tau? Saya nak ambil gambar tau?" I told myself maybe she didn't mean it but I seriously think she need to learn how to speak politely especially to someone older or senior than you. Even among ourselves as peers, we are polite in some way when asking for favours even though we are quite 'buddy'.
I totally agree with my friend's words that they should've planned their work before they start. Not to look for an umbrella only when it starts raining. Undergrads from my lab are also doing the same thing. Our lab assistant also told me that she had to wait for them to finish their work. And I think they are a bit selfish and being wasteful. Not all of them but some do things according to their convenience and do not plan before they act. Initially I thought because they are new to the lab, so I'm being patient with them. Nagging a bit here and there. But now I think they are taking things for granted, and take advantage on my good will, so some actions has to be taken. I'm meeting them up next week to get things straight for one and for all.
Even if they're going to dislike me, I have to 'teach' them the right way to do things. A scientist takes more than just good data to be able to go further. It takes also good attitude!