LIKE operator and string comparison

I used the following SQL code to match '\foo\bar'

SELECT text FROM test WHERE text LIKE '\\\\foo\\\\%'

But if I choose to use string comparison, instead of 4 escape characters, I 
only need 2.

SELECT text FROM test WHERE text = '\\foo\\bar'

Why is that?

I am using PostgreSQL 7.4, and the SQL code was entered through psql.

Thanks!

Wei