‘No.’ Sarah shook her head. ‘He went around the back.’

I set off to look for him, circling the administration block, checking the toilets, questioning the canteen staff and peeking into every classroom. At last I found him hiding under a demountable. It was a quiet spot behind a bush, out of bounds to most students.

I hunkered down nearby. ‘Hey, Aaron.’

He didn’t move, but I could hear his ragged breathing. I could also see his silhouette, dark against a square of light that was framed between two brick piers.

‘It’s silly to make a fuss about cockroaches,’ I said. ‘Do you know some people keep cockroaches as pets? I used to teach a boy in Sydney called Josh who had a giant burrowing cockroach. He kept it in a fish tank and fed it gum leaves and vegetables. And it was so clean he only had to change its dirt every three months.’

Aaron’s head swung towards me.

‘Cockroaches are really strong too,’ I told him. ‘They can survive anything. And you know what? They can live for a week without a head.’

There was a shuffling noise. Aaron muttered, ‘No, they can’t.’

‘They can. It’s true.’ Josh had told me all about it, and he was right. I’d looked it up. ‘The reason they die is they don’t have a mouth, so they can’t drink or eat. But they only have to eat once a month. And they can hold their breath underwater for half an hour.’

By this time Aaron was inching towards me. ‘Can they swim?’ he asked.

‘I don’t know. They can float. And run. Cockroaches are one of the fastest insects in the world.’ Josh had told me that too. We’d had a lot of conversations about cockroaches because he hadn’t been interested in much else. ‘If they were as big as people, they’d be faster than a car.’

I kept talking about cockroaches until I managed to lure Aaron out from under the classroom. He was so absorbed he didn’t even notice when I took his hand. I led him back to where his sandwich still lay on the hallway floor, and we discussed what to do with it. In the end we decided to throw it away and order another one from the canteen.

‘Do cockroaches like bread?’ Aaron asked in his croaky little voice, as we dumped his lunch in the bin.

‘Absolutely.’

‘Where have they gone?’ He looked around.

‘I don’t know. Maybe they’re scared.’

‘I’m not scared.’ He thought for a moment. ‘Not like Phoebe.’

‘No. Phoebe was scared. That’s why you shouldn’t have pushed her.’

He scowled.

‘Maybe if we tell her how interesting cockroaches are, she’ll stop being scared of them,’ I suggested. ‘Maybe we should have a lesson about cockroaches. Do you think?’