thanks for all the responses.
i agree, when animals become pests there is often no choice but to kill them. in areas where there are deadly snakes and scorpions, i can see that too - esp. if you have children and don't know how to remove them safely. this is not done for fun or to be cruel. i didn't understand why kites are included tho.
ants are also among the animals i will kill when they come in the house and take over, which they do where i live.
thanks for sources of the dog stories (i only knew one). i find these especially admirable.
didn't like this one tho:
"One morning Allah's Messenger was silent with grief. Maymunah said: Allah's Messenger, I find a change in your mood today. Allah's Messenger said: Gabriel had promised me that he would meet me last night, but he did not meet me. By Allah, he never broke his promises; and Allah's Messenger spent the day in this sad (mood). Then it occurred to him that there had been a puppy under their cot. He gave an order and it was turned out. He then took some water in his hand and sprinkled it on the place. When it was evening Gabriel met him and he said to him: You promised me that you would meet me the previous night. He said: Yes, but we do not enter a house in which there is a dog or a picture. So the very next morning he commanded the dogs to be killed. He announced that the dog kept for the orchards should also be killed, but he spared the dog used for the protection of extensive fields (or big gardens)."
this concept i like especially, but i guess there is no source to verify it.
"Lastly, all animals are muslim and worship Allah swt just as we do.
this is true...and even for the plants, trees and rocks....etc"
if anyone can find any source for this concept, i'd really appreciate it.
i don't really understand the one about salamanders and they are not mentioned in the category of animals that it is halal to kill. but i did notice that killing them was to be done as less cruely as possible.
as for killing spiders - from the "killing spiders?" thread:
"Only after several months did Allah grant the Prophet (peace and blessings be upon him) permission to leave Makkah. Shortly before his departure, Jibreel (Angel Gabriel) told Muhammad that the Quraysh had devised a plot to stab him while he was sleeping. On the night of the planned assassination, his cousin `Ali ibn Abi Talib slept in Muhammad’s bed while the latter escaped with his friend Abu Bakr As-Siddiq to a cave south of Makkah, opposite the direction to Madinah. Fortunately for `Ali, the assassins looked at his face before stabbing him and left him alone when they realized they had been outwitted.

Muhammad and Abu Bakr hid in the cave for three days while the Quraysh searched all around Makkah. At one point, their enemies were only a few feet away outside the cave, but Allah protected them by simple everyday “miracles.” A spider spun its web across the mouth of the cave, pigeons nested and laid eggs in front of it, and the branches of a small tree blocked it. Thus the pursuers assumed no one had entered the cave recently and did not search it."
thanks again, everybody for your responses. if you think of anything else, i'd appreciate it.