Cain and Abel fought the bitter fight

Like baby eagles, sharks and all that bite

For parents stand aloof as if amused By sibling killing sibling for their food

This may be the crime original

So common it may seem to be banal

Inside the heart of love lurk greed and hate

Genetics brings destruction as a fate

So hatred precedes love if any grows

As dead egrets have no claw to show.

Families have their scapegoats all will harm

No-one seems to notice wild alarm So Cain was not unusual nor mad Indeed he was a hero, that is sad.

One tension-relieving exercise, the tantrum, involves lying on your bed, banging your fists against the mattress while waggling your legs The Guardian 12 Feb 2021