Awful smell?

I had this problem years and years ago. I tried crawling under but the dead thing was all the way at the end. I ended up taking the skirting off of the end and then having to take the insulation out and replaced it. The smell will last for a long long time if you don't! A feral cat had birthed a dead kitten into the insulation :oP bleerrgghh!! Another time I found a dead opposum under there. After that I got in touch with the DNR and they told me to put a rag that had been soaked in ammonia under there to deter any more animals from getting under there- it worked!

If its a dead cat, then the smell is probably gonna last for a pretty long time. You could try calling some company, or the fire department to try to get it out if its really that bad. It could also just be a mouse, in which case the smell shouldn't last too long.

You need to hire an exterminator to get rid of the Black Widows and perhaps hire someone to come out and remove the cat. That smell will last for a long time. You need to get it out of there.

Sounds lovely. How about calling a professional out to find out the answer for you? Do you really want to just mask the smell? Wouldn't it make more sense if you removed the source of the smell? Just Google "pest removal" and let them know there are spiders present.

You could spray OdoBan around the vents and all, it absorbs smell pretty quick. We had a cat die under our house once and it stunk for a while.

the smell will last for a long long time it wont go away untill the animal has decomposed and is just bones