まさか、寝ぐらにしてるのか？
What I don't know is the phrase '寝ぐら'. I guessed it is a grammatical clause but the search came up with no optimistic result.
However, with the search engine, I found that the Japaneses used it very often in forums and blogs, such as '寝ぐらになる'.
Can anyone tell me the meaning and the grammar behind it, thanks.
寝ぐら is a nonstandard writing form of the word ねぐら (塒), which means bird's roost, and by extension, animal den or lair, and also in the way these English words could describe that of human.
寝ぐらにしてる = 塒にしている be using as one's sleeping spot
Some Japanese words that can be decomposed into multiple units, even if they have kanji as a whole, are occasionally written in combination of kanji that represent a part of the word.
卵【たまご】：玉【たま】子【ご】
偏【かたよ】り：片【かた】寄【よ】り
邪【よこしま】：横【よこ】しま
Sometimes it could be helpful to search an unknown wordform in all hiragana to find the word you want.
