TWO RHYMING RIDDLES

1)
Three eight-letter words I ask of thee,
Letters three, four, and five the same in all three;
Each has a T, and in the same place,
Each has four vowels, but of A there's no trace.

The first's a mistake, the second a tree,
The third a pest that stings like a bee.

2)
I have no mouth, and yet I scream,
To the annoyance of all those around;
But not to the one who summoned me,
Who gladly welcomes my sound.

HINT:
1. The third, fourth, and fifth letters are SQU.

Answers:

1. MISQUOTE / MESQUITE / MOSQUITO 
2. The siren of an emergency vehicle