Premolt abdomen ?

I believe pre-molt, but tarantulas can lose hairs without you witnessing them kick. Tarantulas lay down urticating hairs inside of their burrows, and in the webbing around their enclosure. This is a defense mechanism that ensures any pesky predator who might come sniffing around gets a nose full of urticating hairs and will send them scampering off to look elsewhere for a meal. Especially in the time leading up to a molt when they are in a very fragile state.

@miss moxie One week ago, I could see her everytime outside her hide but now she stays inside. She ate yesterday tho, maybe she will enter into a premolt stage really soon .

Thanks for the informations , you said things I didn't know, like the urcating hairs on the web to repel predators, that's interesting