What a poem's not

A poem is not an Ant
but it can be quite short.
A poem is not a Banana
but there may be something under its skin.
A poem is not a Coat
but it may have some warmth in it.
A poem is not a Dog
but it might be quite a friend.
A poem is not an Endless pair of trousers 
but it can be quite long.
A poem is not a Football shaped like a cucumber.
A poem is not a Great number of things. 
A poem is not a Hedgehog
but it might be hard to get hold of.
A poem is not an Igloo
but it can feel like home.
A poem is not a Jumble sale,
but it might contain some rubbish.
A poem is not a Kite
but it might enjoy the wind.
A poem is not a Lightbulb
but you can change it if you want to.
A poem is not a Monkey
but can be quite human.
A poem is not a Nut
but you can give it to a monkey.
A poem is not an Opera score or an open score
but it can be revealing.
A poem is not a Prison
and it shouldn't feel like one either.
A poem is not a Question...
actually it is sometimes.
A poem is not a Radio
but you may have to tune into it.
A poem is not a Slot machine
but you may have to put something into it.
A poem is not a Toothbrush
So don't clean your teeth with it.
A poem is not an Umbrella
but it can give you protection.
A poem is not a Verruca
and I'm glad.
A poem is not a Wig
but maybe it will change you.
A poem is not an X-ray:
make no bones about it.
A poem is not a Year-old bag of vegetables
but it can smell quite strongly.
A poem is not a Zylophone
and it can spell words wrongly.