Hi in this sentence 'らしく' is used, but I am not really sure about the meaning of らしく. I found this explanation for it, but it doesn't helps me to understand its meaning in the sentence:
- way to use 「らしい」 is to indicate that a person seems to be a certain thing due to his behavior.
誰かの視線に気づいたらしく、ふっと頭を上げ、通りのむこうからこちらの様子をじっとうかがっている猫を見つけた。