A Kangaroo

When I was there, I only saw a few of them but on the TV there were lot of them and they sometimes appeared in the garden of the people's house.

They also hurt to some of people in there.["in there" isn't necessary, but, you can put it if you really want to.]

The government tried killing them but people who were taking care of animals didn't want to do that.

I can't to explain anymore about the program but I also didn't want to kill to them. [Good! I agree ^^どうぶつー大好き<3]

However, if while I was asleep a kangaroo came to my bed and hurt me, how scare about them. [Do you mean you would be scared OR you would scare them?]

I understand both situations.

Why did the kangaroos come down to the town?

Was it because of humans did something? [You can also say: "Was it because of something humans did?" Both ways are correct.]

Was there not enough grasses for the kangaroos to live in there?

They look cute when I see them and I love to see them.

When they standing up with their legs or scratching their body with their arm, it looks like really human...

I thought that they are lucky because they can observe the outside only if they want to it.

The human sometimes may have to look at the outside even if we don't want to it.[Instead of 'sometimes may' for this sentence, you can change it to 'may sometimes'.]

But I sometimes look for a reason why I don't want to look it and it is interesting.

I saw the view in Australia where I have been. [You can say instead 'where I've been'.]

I loved it their.