First, the boys appear to have been acting even more courteously than usual.
Second, they seem to be more excited about going to classes all of a sudden.
And third, more of the boys have been making use of the library at lunch times rather than the sports fields.
Why? Because for the first time in John McGlashan College's history, girls are studying at the school full time.
Their school, St Margaret's College in Christchurch, had been damaged by the earthquake last month.
Katherine Harper, Maddie Mark, Charlotte French and Diana Chen have tried to make the most of the disruption caused to their education, and have come to the other South Island school which offers the International Baccalaureate secondary school qualification.
While their whole world seemed a bit topsy turvy since the quake, the girls admitted they were enjoying the attention.
"We feel a little out of place - we stand out a lot.
"It's nice to be the centre of attention, but this is crazy," Maddie said.
However, Katherine said it was not entirely a bad experience.
"I'm quite enjoying it actually."
The girls said the teachers had been very supportive and were mindful as to their welfare.
"Even the boys are quite good. They are very keen to get to know us," Katherine said.
Principal Mike Corkery assured parents the girls' presence was not permanent but the girls would be welcome as long as they needed to be there.
To avoid any possible breach of the school's integration agreement, the girls had been enrolled at St Hilda's Collegiate School but were attending classes all day at John McGlashan.
Mr Corkery said the schools shared teaching resources, and often girls from St Hilda's would attend one or two classes a week.
But this was the first time girls had been fully integrated into all classes at the boys' school.
He did not deny there had been some strange and awkward behaviour among the boys since the girls from St Margaret's College arrived.
"There may be a bit of silliness around the edges. But we're doing our best to deal with it.
"Surprisingly, there have been boys found in places they wouldn't normally go - like the library."
While there had been some minor inconvenience created by having girls on the school's grounds, Mr Corkery said it was nothing compared with the difficulties people were having in Christchurch.
"We're pleased to be able to help out in this way."