The Prophet ﷺ said: We have not made peace with them since we fought with them, so he who leaves any of them alone through fear does not belong to us. (Using translation from Abū Dāʾūd 5248)
قَالَ رَسُولُ اللهِ ﷺ لِلْحَيَّاتِ مَا سَالَمْنَاهُنَّ مُنْذُ حَارَبْنَاهُنَّ فَمَنْ تَرَكَ شَيْئًا خِيفَتَهُنَّ فَلَيْسَ مِنَّا