Would you please explain to me the Hadeeth in which it is mentioned that Satan whispers to a mouse to turn over the lamp on its head, so as to burn the house down? Why does Satan not do it himself? Also, could you please tell me about the morphology of the Jinn?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Him, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is narrated in Saheeh Muslim and other compilations of Hadeeth, that the Prophet, sallallaahu ‘alayhi wa sallam, advised Muslims to cover their utensils, tie close the water skins, shut the doors and blow out the lamps, because Satan does not open the containers of water, unbolt the doors or uncover the dishware [to enter it]. He, sallallaahu ‘alayhi wa sallam, also suggested that if one finds nothing to cover a bowl with, he may place a stick across it, after saying, "In the Name of Allaah". The Prophet, sallallaahu ‘alayhi wa sallam, further warned Muslims that a mouse might set fire to a house, or, according to another narration, drag the wick and contribute to burning the house down.

Al-Mubaarakfoori in the course of explaining this Hadeeth, said that the scholars highlight the inability of Satan to undo fastened water skins, open closed doors or uncover bowls, provided that the Name of Allaah The Almighty has been mentioned.

Now, since he can neither do those things nor set fire to anything, Satan makes a mouse do it. Ibn ‘Abbaas narrated that a mouse once scurried along, dragging a wick until it dropped it on a mat the Prophet, sallallaahu ‘alayhi wa sallam, was sitting on, whereby, a small part of it burned. Therefore, he, sallallaahu ‘alayhi wa sallam, ordered Muslims to blow out their lamps before they sleep, telling them that Satan whispers to mice and other creatures to do such things to start a fire. [Abu Daawood, Al-Haakim and Ibn Hibbaan]

An-Nawawi said that this Hadeeth contains many useful recommendations for this life and the Hereafter. The Prophet, sallallaahu ‘alayhi wa sallam, ordered Muslims to observe these habits so as to safeguard themselves from Satan’s harm, such that he becomes unable to uncover a bowl, untie a water skin, open a door or harm a child.

Similarly, this Hadeeth is supported by another authentic narration in which the Prophet, sallallaahu ‘alayhi wa sallam, mentioned that when one says “In the Name of Allaah, The Most Merciful, the Ever Merciful” upon entering the home, Satan and his allies are unable to cross the threshold. Also, whenever one has intercourse with his wife, and says, “Allaahumma jannibna ash-shaytan wa jannib ash-shaytaan ma razaqtana” (O Allaah, keep Satan away from us and from our offspring), it wards off Satan’s harm from their baby. There are other authentic Hadeeths which teach Muslims similar habits and etiquettes. 

The Hadeeth [you quoted] also underlines the importance of reciting Athkaar (phrases of remembrance of Allaah The Almighty) in all situations.

We have no information about the morphology of the Jinn.