Who takes the souls of animals and what is their fate?
Question

                When animate beings other than humans, namely animals and birds, die, where do their souls go? Does the Angel of death take them, or what exactly happens to them?
Praise be to Allah.
    Allah, may 
    He be glorified, tells us that the Angel of death takes the souls of the 
    sons of Adam, as He says (interpretation of the meaning): 
    “Say: 
    "The angel of death, who is set over you, will take your souls, then you 
    shall be brought back to your Lord."” 
    [as-Sajdah 32:11]. 

    With 
    regard to the souls of animals and birds, there is no text that speaks about 
    them in the Qur’an or saheeh Sunnah, as far as we know. Rather what has been 
    narrated concerning that is a hadeeth that is not sound (saheeh). This is a 
    report that was narrated by al-‘Aqeeli in ad-Du‘afa’: “The lifespan 
    of all animals, lice, fleas, locusts, horses and mules, all of them, cattle 
    and so on, their lifespans are all connected to their tasbeeh. When their 
    tasbeeh comes to an end, Allah takes their souls, and the Angel of death has 
    nothing to do with that.” Al-Albaani said in as-Silsilah ad-Da‘eefah 
    (4/188): It is mawdoo‘ (fabricated). 

    Hence some 
    of the scholars said that the Angel of death is the one who takes the souls 
    of all creatures, whilst others said that Allah takes their souls Himself 
    and causes their life to cease.

    See: 
    at-Tadhkirah by al-Qurtubi, p. 75; al-Fawaakih ad-Dawaani, 1/100 

    Shaykh Ibn 
    ‘Uthaymeen (may Allah have mercy on him) is of the view that asking about 
    that is unnecessary. He (may Allah have mercy on him) was asked: Is the 
    Angel of death appointed to take the souls of animals? 

    He 
    replied:

    What would 
    you think if I said that the Angel of death is or is not appointed to take 
    the souls of animals; what benefit is there in knowing this? Did the 
    Sahaabah ask the Messenger (blessings and peace of Allah be upon him) about 
    that, when they were more eager than others to seek knowledge, and the 
    Messenger was more able than others to answer, yet despite that they did not 
    ask? Rather Allah, may He be glorified and exalted) says (interpretation of 
    the meaning): “Say: 
    ‘The angel of death, who is set over you, will take your souls, then you 
    shall be brought back to your Lord.’” 
    [as-Sajdah 32:11]. 
    He (the Angel of death) is appointed to take the souls of the sons of Adam; 
    with regard to the souls of creatures other than the sons of Adam, nothing 
    is proven. And Allah knows best. 

    But the 
    most important thing to say in response to this question is that man should 
    not go to extremes (inasking questions). The Prophet (blessings and peace of 
    Allah be upon him) said: “Those who go to extremes (in their words and 
    deeds) are doomed.” So do not ask about things in which there is no benefit. 
    By Allah, if there were any benefit in our knowing whether the Angel of 
    death takes the souls of other creatures, Allah, may He be glorified and 
    exalted, would have told us about it, either in the Qur’an or Sunnah, or 
    Allah would have caused someone to ask the Messenger about that. Hence the 
    Sahaabah would rejoice when a Bedouin came from the desert to ask about 
    something that they might feel too shy to ask the Messenger about. 

    The point 
    is, for you and anyone else who is listening, that delving deeply into such 
    matters is wrong, because the Messenger said: ““Those who go to extremes (in 
    their words and deeds) are doomed.” And on one occasion he said: “Those who 
    go to extremes (in their words and deeds) are doomed, those who go to 
    extremes (in their words and deeds) are doomed, those who go to extremes (in 
    their words and deeds) are doomed”, three times. With regard to such matters 
    of the unseen, you should take what has been proven and leave that which has 
    not been mentioned… With regard to matters of the unseen, we should take 
    that which has been proven to us, and as for the rest, we should keep quiet 
    about it; if it was important for us, or if there were any interest to be 
    served by knowing it, Allah would have explained it. Allah, may He be 
    exalted, said to the Messenger (blessings and peace of Allah be upon him):

    “And 
    We have also sent down unto you (O Muhammad SAW) the reminder and the advice 
    (the Quran), that you may explain clearly to men what is sent down to them”

    
    [an-Nahl 16:44].

    The 
    Messenger (blessings and peace of Allah be upon him) did not leave anything 
    that we need but he explained it to us.

    End quote 
    from Liqa’ al-Baab al-Maftooh, 11/146 

    Secondly: 

    With 
    regard to the fate of the souls of these animals, it was narrated by ‘Abd 
    ar-Razzaaq in his Musannaf, by Ibn Jubayr, and by al-Bayhaqi in 
    al-Ba‘th from Abu Hurayrah, that he said concerning the verse 
    (interpretation of the meaning), “There 
    is not a moving (living) creature on earth, nor a bird that flies with its 
    two wings, but are communities like you. We have neglected nothing in the 
    Book, then unto their Lord they (all) shall be gathered” 
    [al-An‘aam 6:38]: 
    All creatures will be gathered on the Day of Resurrection, animals, beasts, 
    birds and everything. Then Allah’s justice on that day will reach such an 
    extent that Allah will settle the score for the hornless animal with the 
    horned one. Then He will say, ‘Be dust,’ at which point the disbeliever will 
    say: ‘Would 
    that I were dust!’ 
    [an-Naba’ 78:40]. 

    See: 
    Tafseer Ibn Katheer, 3/255 

    Al-Albaani 
    said in as-Silsilah as-Saheehah (4/466): This was narrated by 
    as-Suyooti in ad-Durr al-Manthoor (6/310), but he did not say 
    anything about its isnaad as he usually does. According to Ibn Jareer 
    (30/17) it is qawiy. End quote. 

    And Allah 
    knows best.