The Prophet ﷺ said: Kill the two black things during prayer, the snake and scorpion. (Using translation from Abū Dāʾūd 921)   

أَمَرَنَا رَسُولُ اللهِ ﷺ بِقَتْلِ الْأَسْوَدَيْنِ فِي الصَّلَاةِ الْحَيَّةِ وَالْعَقْرَبِ  

[Machine] Narrated Aisha, the wife of the Prophet ﷺ , said: The Messenger of Allah ﷺ used to pray in the house. Ali ibn Abi Talib, may Allah honor his face, came and entered. When the Messenger of Allah ﷺ saw him praying, he stood next to him and prayed. Then, a scorpion approached the Messenger of Allah ﷺ until it reached him. The Prophet ﷺ left it and it went towards Ali. When Ali saw that, he struck it with his shoe, and the Messenger of Allah ﷺ did not punish him for killing it.  

عَنْ عَائِشَةَ زَوْجِ النَّبِيِّ ﷺ قَالَتْ كَانَ رَسُولُ اللهِ ﷺ يُصَلِّي فِي الْبَيْتِ فَجَاءَ عَلِيُّ بْنُ أَبِي طَالِبٍ كَرَّمَ اللهُ تَعَالَى وَجْهَهُ فَدَخَلَ فَلَمَّا رَأَى رَسُولَ اللهِ ﷺ يُصَلِّي قَامَ إِلَى جَانِبِهِ يُصَلِّي قَالَ فَجَاءَتْ عَقْرَبٌ حَتَّى انْتَهَتْ إِلَى رَسُولِ اللهِ ﷺ ثُمَّ تَرَكَتْهُ وَأَقْبَلَتْ إِلَى عَلِيٍّ فَلَمَّا رَأَى ذَلِكَ عَلِيٌّ ضَرَبَهَا بِنَعْلِهِ فَلَمْ يَرَ رَسُولُ اللهِ ﷺ بِقَتْلِهِ إِيَّاهَا بَأْسًا  

[Machine] The Messenger of Allah, ﷺ , said: "It is enough for you to strike the snake once with a whip, whether you hit it or miss it. And if this is true, then Allah knows best about the sufficiency of it in fulfilling the duty of killing it. And Allah knows best, if it refrains from itself upon making a mistake and there is no intention to prevent it from striking more than one blow."  

قَالَ رَسُولُ اللهِ ﷺ كَفَاكَ الْحَيَّةَ ضَرْبَةٌ بِالسَّوْطِ أَصَبْتَهَا أَمْ أَخْطَأْتَهَا وَهَذَا إِنْ صَحَّ فَإِنَّمَا أَرَادَ وَاللهُ أَعْلَمُ وُقُوعَ الْكِفَايَةِ بِهَا فِي الْإِتْيَانِ بِالْمَأْمُورِ فَقَدْ أَمَرَ ﷺ بِقَتْلِهَا وَأَرَادَ وَاللهُ أَعْلَمُ إِذَا امْتَنَعَتْ بِنَفْسِهَا عِنْدَ الْخَطَأِ وَلَمْ يُرِدْ بِهِ الْمَنْعَ مِنَ الزِّيَادَةِ عَلَى ضَرْبَةٍ وَاحِدَةٍ  

The Prophet ﷺ said: If anyone kills a gecko with the first blow, such and such number of good deeds will be recorded for him, if he kills it with the second blow, such and such number of good deeds will be recorded for him less than the former; and if he kills it with the third blow, such and such number of good deeds will be recorded for him, less than the former. (Using translation from Abū Dāʾūd 5263)   

قَالَ رَسُولُ اللهِ ﷺ مَنْ قَتَلَ وَزَغَةً فِي أَوَّلِ ضَرْبَةٍ فَلَهُ كَذَا وَكَذَا حَسَنَةً وَمَنْ قَتَلَهَا فِي الضَّرْبَةِ الثَّانِيَةِ فَلَهُ كَذَا وَكَذَا حَسَنَةً أَدْنَى مِنَ الْأُولَى وَمَنْ قَتَلَهَا فِي الضَّرْبَةِ الثَّالِثَةِ فَلَهُ كَذَا وَكَذَا حَسَنَةً أَدْنَى مِنَ الثَّانِيَةِ وَفِي حَدِيثِ خَالِدٍ دُونَ الْأُولَى وَقَالَ لِدُونِ الثَّانِيَةِ وَالْبَاقِي سَوَاءٌ  

[Machine] "On the authority of the Prophet ﷺ , he said regarding the first strike, it is equivalent to seventy blessings."  

عَنِ النَّبِيِّ ﷺ أَنَّهُ قَالَ فِي أَوَّلِ ضَرْبَةٍ سَبْعِينَ حَسَنَةً  

[Machine] "It is a scorpion."  

أَنَّهَا عَقْرَبٌ