Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: If your parents call you when you are praying, it is obligatory to answer them, on condition that the prayer is not an obligatory one. If it is an obligatory prayer, it is not permissible to answer them, but if it is a naafil prayer, you should answer them. But if they are people who give things their due measure and if, when they realise that you are praying, they will excuse you, then in this case you should indicate to them that you are praying – either by clearing your throat or saying “Subhaan Allah” or raising your voice in the verse or du‘aa’ you are reciting – so that the one who is calling will realise that you are praying. But if they are otherwise, and they are people who will not make excuses or who want an immediate response, then you should interrupt your prayer and speak to them. But in the case of an obligatory prayer, you should not interrupt it for anyone except in the case of necessity, such as if you see someone who you fear will fall into mortal danger, such as falling into a well or into the sea or into a fire. In that case, you should interrupt your prayer because it is a case of necessity. Otherwise, it is not permissible to interrupt an obligatory prayer. End quote. Sharh Riyaad al-Saaliheen, p. 302
The scholars of the Standing Committee were asked: Is it permissible to stop praying if the worshipper sees an animal coming towards him such as a scorpion or other poisonous animal? Similarly, when praying in al-Haram, is it permissible to stop praying so that he can follow his son or daughter who is about to get separated from him and lost? They replied: If it is easy for him to get rid of the scorpion etc without stopping the prayer, then he should not stop praying, otherwise he may stop. Similarly if it is easy for him to look after his child without stopping the prayer, he should do so, otherwise he may stop it. End quote. Shaykh ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan. Fataawa al-Lajnah al-Daa’imah li’l-Buhooth al-‘Ilmiyyah wa’l-Ifta’ (8/36, 37)