Is Killing Snakes Allowed in Islam?
Question

We live in an area that is pretty secluded and as such, it is frequented by many dangerous and venomous snakes.
We're a family of 14 (8 Adults and 6 Kids) and I fear for their safety. We've so far called Wildlife Rescue units every time we have spotted snakes, but they only oblige if the snake is in the vicinity of a home. They refuse to come if the snake is found outdoors/open areas. 
My questions are the following:
1. Can I kill these snakes for the only reason of Safety of family members?
2. I know that Jinns take the form of snakes, so what is the ruling on killing them?
3. Is it true that killing a snake that is a Jinn brings bad luck?
Please also note that we have spent enough money on cleaning and leveling adjacent vacant lands and spraying chemicals to keep snakes and rodents away, but nothing has helped so far. 
Please answer at your earliest convenience. May Allah (Subhana Wa Ta A'la) bless you for the great job you are doing. May you be blessed and rewarded for every letter that is thought of and typed.
Praise be to Allah.The Messenger (blessings and peace of Allah be upon him) enjoined the killing of snakes , and this is general in meaning and applies to all kinds of snakes, in any place. But if the snake is inside the house, it should not be killed until it has been warned three times; that is because of the possibility that it may be a jinn . Then if it appears after that, it may be killed.
It was narrated from Ibn `Umar (may Allah be pleased with him) that he heard the Messenger of Allah (blessings and peace of Allah be upon him) address the people from the pulpit, saying: “Kill snakes.”
`Abdullah ibn `Umar (may Allah be pleased with him) said: “After that, I would not leave any snake that I saw but I would kill it.” (Narrated by Al-Bukhari, 3299 and Muslim, 3233)
Abu Dawud (5249) narrated that Ibn Mas`ud (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Kill all the snakes, and whoever fears their revenge does not belong to me.” (Classed as authentic by Al-Albani in Sahih Abu Dawud)
Muslim (2233) narrated that Nafi` (may Allah have mercy on him) said: One day `Abdullah ibn `Umar (may Allah be pleased with him) was at a ruin of his, when he saw the flash of a small snake. He said: Find this snake and kill it. Abu Lubabah Al-Ansari s(may Allah be pleased with him) aid: I heard the Messenger of Allah (blessings and peace of Allah be upon him) forbid killing the small snakes that live in houses, except the short-tailed snake and the one with two stripes, for they are the ones that cause blindness and miscarriages.
And Muslim (2236) narrated that Abu As-Sa’ib said: We entered upon Abu Sa`id Al-Khudri, and whilst we were sitting there, we heard a movement beneath the bed. We looked and saw a snake… and he quoted the Hadith, in which it says: The Messenger of Allah (blessings and peace of Allah be upon him) said: “These houses have inhabitants. If you see any of them, ask them to leave for three days. If it goes (all well and good), otherwise kill it, for it is a Kafir.”
Ibn `Abd Al-Barr (may Allah have mercy on him) said:
“Some scholars said: It is not essential for snakes to be warned or urged or asked to leave except in Madinah only. Others said that Madinah and other places are the same in that regard, because some snakes are jinn and may be found in Madinah and elsewhere, and whoever among them Allah wills may be Muslim. Malik said: What I prefer is that the snakes that are found in houses, in Madinah and elsewhere, should be warned for three days, but snakes should not be warned if they are found in the desert.”
Ibn `Abd Al-Barr (may Allah have mercy on him) said:
“It is preferable that all snakes that are found in houses should be warned, as Malik said. What is meant by warning is that the person who sees a snake in his house should say: I urge you, O snake, not to appear before us or harm us.” (At-Tamhid, 16/263)
Ibn `Abd Al-Barr (may Allah have mercy on him) said:
“The scholars unanimously agreed that it is permissible to kill desert snakes, whether they are small or large, no matter what type they are.” (At-Tamhid, 16/28)
So there is nothing wrong with you killing snakes that are outside the house. As for those that are found inside the house, they should not be killed until they have been warned for three days.
With regard to the view that killing the jinn that appear in the form of snakes brings bad luck, this is a false view for which there is no basis.
For more details, please see the following answers: 1239 , 21901 , 8814 , 2896 , 8804 , and 127221 .
And Allah knows best.