hissing mother

[sage]

millie had her hoglets yesterday and this is my first time raising hoglets. I wasn't prepared for her to have babies. I cant see them because they are under the blanket but I can hear them. millie keeps hissing at them (i think) like they startled her. i also have a lamp over them to keep them warm. i need advaise quickly on what to do. i have done resarch but cant find anything on why she is hissing at her babies and i know its not because its me because she does it at night when im in bed. Please help me.

[sage]

and another thing what is a good way to keep them warm. my father says space heaters are to dangerous. i have very limited things i can do im only in high school and no job