"Locust" is appropriate to the mainland visitor situation in Hong Kong only insofar as locusts arrive in swarms. The comparison ends there because real-life locusts ruthlessly devour crops, causing widespread devastation, then take their ruination elsewhere.

Our mainland visitors spread wealth among most of those they come into contact with. Admittedly, while they spend their money some are given to bad behaviour. They are acutely aware they are disliked here, and are always on guard against being cheated. Not surprisingly, they retaliate by being suspicious, nasty and so on.

So are their Cantonese hosts as a whole well-behaved, courteous, mild-mannered, scrupulously honest and polite to a fault? Whether from Beijing, Shanghai, Sham Shui Po or Sha Tin, we all have faults. But the enduring qualities of the Cantonese comprise their basic decency, resilience, capacity for hard work, desire to prosper and provide a decent home for their families, and especially to give their children a good education.

Following the Japanese occupation of 1942-45, Hong Kong emerged in an appalling state both physically and economically. The only resources it possessed were the muscles and sweat of a workforce willing to slog it out hour after hour in cramped factories and workplaces. Heroically, those men, and not a few women, too, slaved for a pittance as the city built up export markets for its modest products. But, soon, a seemingly endless torrent of refugees was pouring into Hong Kong from neighbouring Guangdong.

They occupied any vacant land, throwing up sprawling squatter settlements, the biggest a shanty town for 53,000 in Shek Kip Mei. But a terrible fire at Christmas in 1953 swept through the huts and left the squatters huddled on the streets in the bitter cold.

The whole area was razed and an urgent building programme launched to house the victims in mini-flats. Families used three-storey bunk beds to squeeze in their children and themselves and thought it quite comfortable. Cooking was done on the balconies, and ablutions were performed in communal toilets.

The squatters actually thought their new homes quite comfortable, and cheerfully paid a monthly rent of HK$14. Schools were set up on the blocks' rooftops - furnaces in summer, iceboxes in winter, and a six-storey climb for children living on the ground floors. Like their parents, the children toughed it out and later contributed their muscle power to Hong Kong's success story.

Shek Kip Mei was the precursor to Hong Kong's massive public housing programme, among the biggest in the world, now with more than two million occupants.

The original tenants of those early estates were, to a great extent, the grandparents of many of today's Hong Kong residents; some became leading lights of our society, including two of our three chief executives. The housing programme was financed and built thanks in part to the sheer grit of these hard-working achievers. And the roots of our present-day generations were watered with the sweat of these doughty forefathers.

Back in the 1950s, 1960s and so on, did the residents of Hong Kong who had lived here since before the Pacific war think of the refugees as "locusts"? No. True, they didn't mix with them much but grudgingly admired and welcomed them as fellow Cantonese who had escaped communal life for the freedom and advantages of Hong Kong.

Is this not a lesson for us all today? Remember Rodney King, the black victim of a cruelly vicious police beating, who said in 1992 in a plea for communal peace in Los Angeles, "Can't we all get along?"

Anger begets anger, insult breeds insult. Some mainlanders are positively unpleasant, but most are not. We are their hosts, and we profit greatly from their visits. Can't we spray the insecticide of common sense into the air and just get along with one another?