They turn up late without doing the required reading and then they sit chatting to their friends, texting or looking bored.
Just when you thought you finally had everyone's full attention, a mobile phone rings, and students start packing up their things 15 minutes before the end of the session.
If this sounds familiar, it is because these are among the most common examples of student "incivility" in university lecture and seminar rooms, according to a new study.
Paula Rivas, a senior lecturer in health at Edge Hill University, surveyed 350 nursing students and 57 teaching staff at a university in North West England.
The respondents reported high levels of disruptive behaviour, with problems ranging from students using their mobile phones during teaching to those arriving dressed in "inappropriate" attire.
About 40 per cent of staff had witnessed students reading magazines or newspapers during class, and 63 per cent had experienced their students falling asleep.
Worryingly, staff also reported behaviour they perceived to be threatening or intimidating.
Verbal abuse of other students had been witnessed by 29 per cent of staff, offensive language by per cent, and 6 per cent had seen one student threaten another.
Ms Rivas, who presented her paper, "An exploratory study of disruptive behaviour and incivility in higher education classrooms" at the British Educational Research Association conference this month, said her research raised interesting questions about the dynamics of student behaviour during teaching sessions.
Young students, aged 23 and under, were more tolerant of disruptions such as texting, listening to iPods, or mobile phones ringing, than mature students.
One 21-year-old said: "Mobile phones are a part of everyday life ... Change with the times, mobile phones are not disruptive!"
However, another student stated: "I am a mature student who has given up a lot to do this course.
"Disruptive classroom behaviour has a serious effect on my learning."
Younger students were more likely to be concerned about mature students dominating discussions in class, with 88 per cent reporting that this disrupted their learning.
One 19-year-old student said: "As a younger student who has recently left school, I am able to work well with background noise and can cope with disruptive behaviour. I appreciate that mature students have not been in this environment for some time, however, they often single out the younger ones. It is often more disruptive when they ask irrelevant questions or share their experiences."
DISRUPTIVE CLASSROOM BEHAVIOURS EXPERIENCED BY STAFF
Behaviour: Frequency %
Chatting in class: 97.1
Mobile phone ringing in class: 94.3
Entering late: 91.4
Texting in class: 90.9
Not being prepared for sessions: 90.3
Preparing to leave early: 85.2
Acting bored/apathetic: 82.4.