wsj: australia’s trump targets the mail , page-61

Not quite as sophisticated, but sophisticated all the same:

http://hippo-box.co.uk/answer.aspx#18

Q.12 What happens if an animal such as my cat gets into the box and gets trapped inside?


A. The Hippo Box has air-holes in the top of the box under the canopy and at the back of the canopy. These allow an air-flow through the box, whilst still keeping it resistant to penetration by rain or snow. We would, however, emphasise that the Hippo Box is not a toy and children should be discouraged from 'playing games' with it.


No wonder Royal Mail has been buying these.