I am a Muslim ... so I have no Doubts, about the Existence of extra-terrestrial Life ...
Because, in Holy Quran, Allah, The Almighty Creator, of the Existent Totality, Says,
" We have Scattered a scattering of 'Daabaat" ... Meaning, four legged, load bearing type of Animals ... throughout the Universe."
But, you should also remember, The Lord Saying,
"We have Created, the Human, in the Best of Symmetries ... Created him, the 'Ashraf ul Makhlooqaat' " Meaning, the Human, is, the Epitome of Creation.
Therefore, while there undoubtedly is Animal life, inhabiting countless Planets in the Physical Universe ... There is none, that is higher in intelligence or superior in Form to the Human.