Are humans a messy species?

Question 1

out of sight, out of mind

Answer 1

said to emphasise that it is easier to forget something when you cannot see it.

In the past, humans got rid of their waste by throwing it into the street or into streams and rivers, hoping the water would wash it away. Right - cats for example dig a hole to bury their poo.
Out of sight out of mind! That’s a phrase used to say that it’s easier to forget something when you can’t see it.

Question 2

go to great lengths

Answer 2

try very hard to achieve something.

Like cats and ants, antelopes go to great lengths, meaning they try very hard to do something, in this case to leave their poo - or dung - in a specific area, away from their home.

Question 3

territorial markers

Answer 3

smells secreted by animals into their dung or urine to mark their territory.

Antelopes leave smells, called territorial markers, secreted in urine, or pee, to tell other animals that an area of land is already occupied.
but just because most of us don’t pee at the bottom of the garden, does that necessarily mean humans are dirtier?

Question 4

disgust

Answer 4

strong feeling of dislike or repulsion.

Our natural reaction to something which is dirty, and which therefore may be diseased and harmful to us, is disgust – a strong feeling of dislike or repulsion.

Question 5

nausea

Answer 5

the feeling that you are going to vomit or be sick.

We might feel so disgusted at the sight or smell of human waste that we actually want to vomit – a feeling known as nausea.
These bodily reactions are the immune system’s way of saying: keep away! – this will make you sick!

Question 6

raise / make a stink about something

Answer 6

make a strong public complaint.

It was only when the smell reached the noses of politicians in Parliament that something was done about it… …so starting another useful phrase – to raise a stink about something, meaning to make a strong public complaint.